Von Aschenbach, born in Silesia to a civil servant and his Bohemian blooded wife, is a well-known writer. He was married for a short time before his wife died and now lives alone in Munich. After an unsatisfactory morning of work, he sets out on a walk and notices a strange looking tourist in a cemetery. Suddenly, von Aschenbach has a desire to travel. He briefly considers following the tourist, but instead takes the tram home.
Von Aschenbach lives an extremely ascetic life, dashing cold water on himself in the morning so that he can wake up and work on his writing. He has no close personal relationships. As a young boy, he was sickly, and has thus lived most of his life in this type of solitude. His literary work has brought him great fame. Usually, he portrays the stories of stoic heroes who appear noble, but are degenerate on the inside.
Two weeks after spotting the strange tourist in Munich, von Aschenbach embarks on a trip. He orders that his house in the German countryside be readied for his return in one month's time. He takes a train to Trieste, then boards a boat to a resort on an island in the Adriatic. Although he enjoys the trip, he is not completely satisfied, and decides to move on to Venice. On the boat, he meets an older man wearing makeup and rouge in an attempt to appear younger and socialize with a group of younger men. Von Aschenbach is disgusted by the man in makeup. When he arrives in Venice, von Aschenbach gets a free gondola ride because the gondolier is unlicensed and shoves off the pier before von Aschenbach has the chance to pay him.
At dinner at the hotel that night, von Aschenbach notices a Polish family of three girls and a beautiful boy of about fourteen, accompanied by a governess. The writer is struck by the boy's beauty. The next morning, he watches the boy, Tadzio, play with a friend on the beach, and then returns to his hotel room to inspect his own wrinkled face and gray hair. Von Aschenbach goes to Venice that afternoon and the oppressive humidity causes him to suffers a feverish attack. With ambivalence, von Aschenbach decides to leave Venice permanently, and tries to catch a train the next day. Unfortunately, his luggage is mislaid. He returns to the hotel, and feels joyful because while staying near Venice he can watch Tadzio, a truth that causes him slight discomfort.
When von Aschenbach's luggage is returned two days later, he unpacks and resolves to stay. Von Aschenbach quickly falls into a routine of watching Tadzio and using his inspiration to write. Walking behind him on the beach one morning, von Aschenbach almost overtakes him and tries to speak to him, but restrains himself. One evening, he runs into Tadzio unexpectedly and cannot control his surprised and excited facial expressions. Tadzio smiles back, aware of his own attractiveness. Von Aschenbach hurries away, and later whispers "I love you," a phrase obviously meant for the boy but only spoken after Tadzio has left.
During his fourth week at the hotel near Venice, von Aschenbach notices that many of the other guests are leaving. He hears rumors of a disease sweeping the city and tries to obtain concrete information about the outbreak. Von Aschenbach realizes that there is a fairly serious problem, but resolves not to leave. Anyone he asks reassures him that the smell of germicide in the city is merely evidence of the police being overly cautious. Von Aschenbach begins to follows Tadzio more actively, tailing the Polish family in Venice and watching the boy at a street musician concert in the hotel garden.
Von Aschenbach begins to alter his appearance to look younger. He adds colorful touches to his clothing, dyes and curls his hair, and wears rouge. All of these actions are behaviors he found despicable when he observed them in a fellow traveler earlier in the novel Although Tadzio realizes von Aschenbach is following him, he does not tell his family. In analyzing his relationship with Tadzio, Von Aschenbach imagines himself as Socrates and Tadzio as Phaedrus, thus fantasizing a relationship that mirrors the Greek Platonic ideal. In a half-awake dream, von Aschenberg predicts he will soon die, and that Tadzio, whom the writer assumes is at the resort because he is sickly, will die soon thereafter. Von Aschenbach witnesses a few of Tadzio's friends roughing him up on the beach. Tadzio walks away and looks back at von Aschenbach, knowing that he is watching. When von Aschenberg finally dies, most likely from cholera, the world is stunned to hear of the death of such a famous man.