As a flute melody plays, Willy Loman returns to his home in Brooklyn one night, exhausted from a failed sales trip. His wife, Linda, tries to persuade him to ask his boss, Howard Wagner, to let him work in New York so that he won't have to travel. Willy says that he will talk to Howard the next day. Willy complains that Biff, his older son who has come back home to visit, has yet to make something of himself. Linda scolds Willy for being so critical, and Willy goes to the kitchen for a snack.
As Willy talks to himself in the kitchen, Biff and his younger brother, Happy, who is also visiting, reminisce about their adolescence and discuss their father's babbling, which often includes criticism of Biff's failure to live up to Willy's expectations. As Biff and Happy, dissatisfied with their lives, fantasize about buying a ranch out West, Willy becomes immersed in a daydream. He praises his sons, now younger, who are washing his car. The young Biff, a high school football star, and the young Happy appear. They interact affectionately with their father, who has just returned from a business trip. Willy confides in Biff and Happy that he is going to open his own business one day, bigger than that owned by his neighbor, Charley. Charley's son, Bernard, enters looking for Biff, who must study for math class in order to avoid failing. Willy points out to his sons that although Bernard is smart, he is not "well liked," which will hurt him in the long run.
A younger Linda enters, and the boys leave to do some chores. Willy boasts of a phenomenally successful sales trip, but Linda coaxes him into revealing that his trip was actually only meagerly successful. Willy complains that he soon won't be able to make all of the payments on their appliances and car. He complains that people don't like him and that he's not good at his job. As Linda consoles him, he hears the laughter of his mistress. He approaches The Woman, who is still laughing, and engages in another reminiscent daydream. Willy and The Woman flirt, and she thanks him for giving her stockings.
The Woman disappears, and Willy fades back into his prior daydream, in the kitchen. Linda, now mending stockings, reassures him. He scolds her mending and orders her to throw the stockings out. Bernard bursts in, again looking for Biff. Linda reminds Willy that Biff has to return a football that he stole, and she adds that Biff is too rough with the neighborhood girls. Willy hears The Woman laugh and explodes at Bernard and Linda. Both leave, and though the daydream ends, Willy continues to mutter to himself. The older Happy comes downstairs and tries to quiet Willy. Agitated, Willy shouts his regret about not going to Alaska with his brother, Ben, who eventually found a diamond mine in Africa and became rich. Charley, having heard the commotion, enters. Happy goes off to bed, and Willy and Charley begin to play cards. Charley offers Willy a job, but Willy, insulted, refuses it. As they argue, Willy imagines that Ben enters. Willy accidentally calls Charley Ben. Ben inspects Willy's house and tells him that he has to catch a train soon to look at properties in Alaska. As Willy talks to Ben about the prospect of going to Alaska, Charley, seeing no one there, gets confused and questions Willy. Willy yells at Charley, who leaves. The younger Linda enters and Ben meets her. Willy asks Ben impatiently about his life. Ben recounts his travels and talks about their father. As Ben is about to leave, Willy daydreams further, and Charley and Bernard rush in to tell him that Biff and Happy are stealing lumber. Although Ben eventually leaves, Willy continues to talk to him.
Back in the present, the older Linda enters to find Willy outside. Biff and Happy come downstairs and discuss Willy's condition with their mother. Linda scolds Biff for judging Willy harshly. Biff tells her that he knows Willy is a fake, but he refuses to elaborate. Linda mentions that Willy has tried to commit suicide. Happy grows angry and rebukes Biff for his failure in the business world. Willy enters and yells at Biff. Happy intervenes and eventually proposes that he and Biff go into the sporting goods business together. Willy immediately brightens and gives Biff a host of tips about asking for a loan from one of Biff's old employers, Bill Oliver. After more arguing and reconciliation, everyone finally goes to bed.
Act II opens with Willy enjoying the breakfast that Linda has made for him. Willy ponders the bright-seeming future before getting angry again about his expensive appliances. Linda informs Willy that Biff and Happy are taking him out to dinner that night. Excited, Willy announces that he is going to make Howard Wagner give him a New York job. The phone rings, and Linda chats with Biff, reminding him to be nice to his father at the restaurant that night.
As the lights fade on Linda, they come up on Howard playing with a wire recorder in his office. Willy tries to broach the subject of working in New York, but Howard interrupts him and makes him listen to his kids and wife on the wire recorder. When Willy finally gets a word in, Howard rejects his plea. Willy launches into a lengthy recalling of how a legendary salesman named Dave Singleman inspired him to go into sales. Howard leaves and Willy gets angry. Howard soon re-enters and tells Willy to take some time off. Howard leaves and Ben enters, inviting Willy to join him in Alaska. The younger Linda enters and reminds Willy of his sons and job. The young Biff enters, and Willy praises Biff's prospects and the fact that he is well liked.
Ben leaves and Bernard rushes in, eagerly awaiting Biff's big football game. Willy speaks optimistically to Biff about the game. Charley enters and teases Willy about the game. As Willy chases Charley off, the lights rise on a different part of the stage. Willy continues yelling from offstage, and Jenny, Charley's secretary, asks a grown-up Bernard to quiet him down. Willy enters and prattles on about a "very big deal" that Biff is working on. Daunted by Bernard's success (he mentions to Willy that he is going to Washington to fight a case), Willy asks Bernard why Biff turned out to be such a failure. Bernard asks Willy what happened in Boston that made Biff decide not to go to summer school. Willy defensively tells Bernard not to blame him.
Charley enters and sees Bernard off. When Willy asks for more money than Charley usually loans him, Charley again offers Willy a job. Willy again refuses and eventually tells Charley that he was fired. Charley scolds Willy for always needing to be liked and angrily gives him the money. Calling Charley his only friend, Willy exits on the verge of tears.
At Frank's Chop House, Happy helps Stanley, a waiter, prepare a table. They ogle and chat up a girl, Miss Forsythe, who enters the restaurant. Biff enters, and Happy introduces him to Miss Forsythe, continuing to flirt with her. Miss Forsythe, a call girl, leaves to telephone another call girl (at Happy's request), and Biff spills out that he waited six hours for Bill Oliver and Oliver didn't even recognize him. Upset at his father's unrelenting misconception that he, Biff, was a salesman for Oliver, Biff plans to relieve Willy of his illusions. Willy enters, and Biff tries gently, at first, to tell him what happened at Oliver's office. Willy blurts out that he was fired. Stunned, Biff again tries to let Willy down easily. Happy cuts in with remarks suggesting Biff's success, and Willy eagerly awaits the good news.
Biff finally explodes at Willy for being unwilling to listen. The young Bernard runs in shouting for Linda, and Biff, Happy, and Willy start to argue. As Biff explains what happened, their conversation recedes into the background. The young Bernard tells Linda that Biff failed math. The restaurant conversation comes back into focus and Willy criticizes Biff for failing math. Willy then hears the voice of the hotel operator in Boston and shouts that he is not in his room. Biff scrambles to quiet Willy and claims that Oliver is talking to his partner about giving Biff the money. Willy's renewed interest and probing questions irk Biff more, and he screams at Willy. Willy hears The Woman laugh and he shouts back at Biff, hitting him and staggering. Miss Forsythe enters with another call girl, Letta. Biff helps Willy to the washroom and, finding Happy flirting with the girls, argues with him about Willy. Biff storms out, and Happy follows with the girls.
Willy and The Woman enter, dressing themselves and flirting. The door knocks and Willy hurries The Woman into the bathroom. Willy answers the door; the young Biff enters and tells Willy that he failed math. Willy tries to usher him out of the room, but Biff imitates his math teacher's lisp, which elicits laughter from Willy and The Woman. Willy tries to cover up his indiscretion, but Biff refuses to believe his stories and storms out, dejected, calling Willy a "phony little fake." Back in the restaurant, Stanley helps Willy up. Willy asks him where he can find a seed store. Stanley gives him directions to one, and Willy hurries off.
The light comes up on the Loman kitchen, where Happy enters looking for Willy. He moves into the living room and sees Linda. Biff comes inside and Linda scolds the boys and slaps away the flowers in Happy's hand. She yells at them for abandoning Willy. Happy attempts to appease her, but Biff goes in search of Willy. He finds Willy planting seeds in the garden with a flashlight. Willy is consulting Ben about a $20,000 proposition. Biff approaches him to say goodbye and tries to bring him inside. Willy moves into the house, followed by Biff, and becomes angry again about Biff's failure. Happy tries to calm Biff, but Biff and Willy erupt in fury at each other. Biff starts to sob, which touches Willy. Everyone goes to bed except Willy, who renews his conversation with Ben, elated at how great Biff will be with $20,000 of insurance money. Linda soon calls out for Willy but gets no response. Biff and Happy listen as well. They hear Willy's car speed away.
In the requiem, Linda and Happy stand in shock after Willy's poorly attended funeral. Biff states that Willy had the wrong dreams. Charley defends Willy as a victim of his profession. Ready to leave, Biff invites Happy to go back out West with him. Happy declares that he will stick it out in New York to validate Willy's death. Linda asks Willy for forgiveness for being unable to cry. She begins to sob, repeating "We're free. . . ." All exit, and the flute melody is heard as the curtain falls.