The play takes place in 1949. The setting is the Loman home in Brooklyn,[9] located amidst a typical row of urban apartment buildings.
Willy Loman suddenly returns home exhausted after a canceled business trip to Boston. Worried over Willy's state of mind and recent car accident, his wife Linda suggests that he ask his boss, Howard, to allow him to work in his home city so he will not have to travel. Willy complains to Linda about their son, Biff, who is 35 years old and has yet to do something with his life. Despite Biff having a promising football career in high school, he failed in mathematics and was therefore unable to enter a university.
Biff and his younger brother, Happy, who is temporarily staying with Willy and Linda after Biff's unexpected return from the West, reminisce about their childhood together. They discuss their father's mental degeneration, which they have witnessed in the form of his constant indecisiveness and daydreaming about the boys' high school years. Eventually, Willy walks in, angry that the two boys have never amounted to anything. In an effort to pacify their father, Biff and Happy tell him that Biff plans to make an ambitious business proposition the next day.
The next day, Willy goes to Howard’s office for a job in town while Biff goes to make a business proposition, but they both fail. Howard refuses to give Willy a New York job, despite Willy's desperate pleas. Willy then loses his temper and ends up getting fired when Howard tells him that he needs a long rest and is no longer allowed to represent the Wagner Company. On the other hand, Biff waits hours to see a former employer who does not remember him and turns him down. In response Biff, feeling crushed, impulsively steals a fountain pen. Willy then goes to the business office of his neighbor Charley, where he runs into Charley's son Bernard, who is now a successful lawyer about to argue a case in front of the Supreme Court. Bernard tells him that Biff originally wanted to go to summer school to make up for failing math, but something happened in Boston when Biff went to visit his father that changed his mind. Charley then offers Willy a stable do-nothing job, but Willy vehemently refuses despite losing his job. Charley, who feels insulted, reluctantly gives the now-unemployed Willy money to pay off his life-insurance premium, and Willy shocks Charley by remarking that ultimately, a man is "worth more dead than alive."
Happy, Biff, and Willy meet for dinner at a restaurant, but Willy refuses to hear the bad news from Biff. Happy tries to coax Biff to lie to their father. Biff tries to tell him what happened as Willy gets angry and slips into a flashback of what happened in Boston the day Biff came to see him: Biff had come to Boston to ask Willy to convince Biff's teacher to curve Biff's failing math grade, so he could graduate. However, Willy was in the middle of an extramarital affair with a receptionist when Biff arrived unexpectedly, and saw the half-dressed woman with him. Biff did not accept his father's cover-up story for her presence, and angrily dismissed him as a liar and a fake before storming out. From that moment, Biff's views of his father changed and set him adrift.
Biff leaves the restaurant in frustration, followed by Happy and two girls that Happy picked up, leaving a confused and upset Willy behind. When they later return home, Linda angrily confronts them for abandoning their father while Willy remains outside, talking to himself. Biff tries to reconcile with Willy, but the discussion quickly escalates into emotional conflict. Biff conveys plainly to his father that he is not meant for anything great, insisting that both of them are simply ordinary men meant to lead ordinary lives. The argument reaches an apparent climax as Biff hugs Willy and begins to cry as he tries to get Willy to let go of his unrealistic expectations. Rather than listen to what Biff actually says, Willy appears to believe his son has forgiven him and will follow in his footsteps, and after Linda goes upstairs to bed, lapses one final time into a hallucination, thinking he is talking to his long-dead wealthy brother Ben. In Willy's mind, Ben "approves" of the scheme Willy has dreamed up to take his own life in order to give Biff his life insurance money to help him start a business. Willy exits the house, and Biff and Linda cry out in despair as the sound of Willy's car blares up and fades out. The car crashes and Willy dies.
The final scene takes place at Willy's funeral, which is attended only by his family, Charley and Bernard (who is the only character to not speak during the final scene). The ambiguities of mixed and unaddressed emotions persist, particularly over whether Willy's choices or circumstances were obsolete. At the funeral, Biff upholds his belief that he does not want to become a businessman like his father. Happy, on the other hand, chooses to follow in his father's footsteps, while Linda laments her husband's decision just before her final payment on the house.
