Death of a Salesman takes place in New York and Boston. The action begins in the home of Willy Loman, an aging salesman who has just returned from a road trip. Willy is having difficulty remembering events, as well as distinguishing the present from his memories of the past. His wife, Linda, suggests that he request a job in New York rather than travel each week. Linda and Willy argue about their oldest son Biff.
Biff and his brother, Happy, overhear Willy talking to himself. Biff learns that Willy is usually talking to him (Biff) during these private reveries. Biff and Happy discuss women and the future. Both are dissatisfied with their jobs: Biff is discontent working for someone else, and Happy cannot be promoted until the merchandise manager dies. They contemplate buying a ranch and working together.
At this point, Willy relives several scenes from his past, including the time when, during high school, Biff admits to stealing a football and promises to throw a pass for Willy during the game. Willy also remembers his old dream of the boys visiting him in Boston during a road trip. Finally in his reverie, he relives the time that Bernard, son of the next-door neighbor Charley, informs Willy that Biff is failing math and will not graduate unless his scores improve. In this last scene, Willy listens but dismisses the important news because Biff is "well-liked," and Bernard is not.
Willy remembers a conversation with Linda in which he inflates his earnings but is then forced to admit he exaggerated when Linda calculates his commission. Willy recalls complaining about his appearance and remembers Linda assuring him that he is attractive. At this point, Willy's memories begin to blend together. While he is reliving his conversation with Linda, he begins to remember his conversation with the Woman (a woman with whom he had an affair). He is unable to separate memories of Linda from the Woman.
The play continues in the present with his neighbor Charley coming over to play cards. However, Uncle Ben appears to Willy while he is playing cards with Charley, and Willy relives an old conversation with Ben while simultaneously talking with Charley. As a result, Willy becomes confused by the two different "discussions" he is having — one in the present, one in the past — and he accuses Charley of cheating. After Charley leaves, Willy relives Ben's visit and asks Ben for advice because he feels insecure since he did not really know his own father. Willy also remembers instructing Biff and Happy to steal some supplies from the construction site in order to remodel the porch so that he can impress Ben.
The play once again returns to the present, in which Biff and Happy talk with Linda about Willy. Biff and Happy learn that Willy is on straight commission and has been borrowing money from Charley in order to pay bills. Linda criticizes her sons for abandoning their father in order to pursue their own selfish desires, and she gives Biff a choice: Respect your father or do not come home. Biff decides to stay in New York, but he reminds Linda that Willy threw him out of the house. He also tells Linda that Willy is a "fake." It is at this point that Linda informs her sons that Willy is suicidal.
Willy overhears his wife and sons talking, and he and Biff argue. When Happy describes Biff's plan to open his own business, Willy directs Biff on what to do during his interview with Bill Oliver. Willy remembers Biff's football games. Before Linda and Willy go to bed, Linda questions Willy: She wants to know what Biff is holding against him, but Willy refuses to answer. Biff removes the rubber tubing Willy hid behind the heater.
The next morning Willy prepares to visit his boss Howard to ask him for a job in New York. During the meeting, Howard informs Willy that there are no positions available in New York. Willy reminds Howard that he named him, and he was a very successful salesman when he worked for Howard's father. Howard remains impassive and instead fires him.
Upon being fired, Willy begins freefalling into his memories of the past. Willy recalls Ben's visit once again. This time, Willy asks for advice because things are not going as he planned. He remembers Ben offering him a job in Alaska. He accepts, but Linda intervenes and reminds him of Dave Singleman. Willy shifts from his memory of Ben to Biff's last football game. Willy recalls Charley pretending he is unaware of Biff's game, and this infuriates Willy. Willy's daydream ends when he arrives at Charley's office.
Bernard is waiting for Charley in his office. Willy and Bernard discuss Biff and consider possible reasons for his lack of motivation and success. Bernard says Biff changed right after high school when he visited Willy in Boston. Bernard questions Willy about what happened when Biff went to visit him. Willy becomes defensive. Bernard is on his way to present a case before the Supreme Court. Bernard's success both pleases and upsets Willy. Charley gives Willy money for his insurance payment and offers him a job, an offer that Willy refuses.
At a restaurant where Willy, Biff, and Happy are to meet, Happy flirts with a young prostitute, and Biff is upset because Oliver did not remember him. Then Biff realizes that he was never a salesman for Oliver; instead, he was a shipping clerk. Willy tells his sons that he has been fired. Biff attempts to explain what happened with Oliver (after seeing Oliver, Biff sneaked back into his office and stole Oliver's pen); however, Willy is reliving the past, recalling Bernard informing Linda that Biff has failed math and will not graduate. Willy then remembers Bernard telling her Biff has taken a train to Boston.
Willy relives the time when Biff finds out about Willy's affair with the Woman: Biff comes to Willy's hotel room in Boston to tell Willy that he will not graduate unless Willy can convince Mr. Birnbaum to pass him. Willy recalls his own desperate attempts to hide the Woman in the bathroom. When the Woman comes out of the bathroom with Biff in the room, Willy's plan to conceal the affair is ruined. Willy's final memory is of Biff calling him a "fake" before walking out the door.
The play continues in the present when Stanley reappears, and Willy realizes he is actually still in the restaurant. Willy returns home and begins building a garden, even though it is night. Linda throws Happy and Biff out of the house. Ben appears to Willy while he is planting seeds. At this point, Willy does not remember a previous conversation with Ben, as he does several times earlier in the play. Instead, he and Ben discuss his plan to commit suicide. Willy and Ben converse in the present, but they are talking about the future. Ben warns Willy that the insurance company might refuse to pay a settlement and Biff might never forgive him.
Biff approaches Willy in the garden to tell him he is leaving home for good. Biff and Willy argue, and Biff confronts Willy with the rubber hose, saying he will not pity him if he commits suicide. According to Biff, the Lomans have never been truthful with one another or themselves. Biff believes that he and Willy are ordinary people who can easily be replaced. Biff and Willy reconcile. Ben reappears to Willy and reminds him of the insurance policy. Willy drives away. The Lomans, Charley, and Bernard gather at Willy's grave.