Willy Loman is a salesman living in New York City in the late 1940's. He lives with his wife, Linda, in the same house for the last twenty-five years. The house once sat apart from other homes, now it is surrounded by apartment buildings, which makes Willy feel closed in.

Willy is having trouble concentrating on driving and often makes mistakes such as crossing the white line, driving off the road, and running red lights, while stopping for green lights. He has begun to talk to himself more and more, which causes concern for Linda. He, at the beginning of the play, has come home from a business trip because he has had trouble with his driving. He is also concerned, because his sons are not progressing in the business world the way he had hoped they would. His son Happy does have a job and lives in his own apartment, but his son, Biff, rambles from job to job, as a farmhand, never making much money.

Willy has been demoted from a salary employee to a commission employee at his job. This means he makes less money to support himself and his wife. This combined with the constant driving and lackluster sales, causes Willy so much stress, that he begins to hallucinate. He thinks he is living in an earlier time in his life. He speaks to people who aren't there and he disturbs his friend, Charley, who comes over to play cards with Willy. During the game Willy thinks his dead brother, Ben, is in the room with them. He is talking to Ben and Charley at the same time, which causes Charley and Willy to have a disagreement about the card game. Charley leaves, but Willy is still talking to Ben asking him how he made his fortune. Ben had gone to Africa and worked in the diamond mines, this is how he became rich. Willy also needs Ben to tell him he is proud of Willy and his sons. During this hallucination the boys are teenagers and Biff is the sports star at his school. Willy sees a very bright future for his son, but in reality this does not come to pass. Willy is not as proud of Happy, who does all he can to garner some attention from his father. He is constantly telling his dad about the weight he has lost, but Willy instead of praising his son, tells him more ways in which to lose weight.

Biff and Happy are surprised at the turn their father has taken. Happy knew his father would often talk to himself, but did not know he was so loud about it and how often it occurred. Biff, meanwhile had no idea his father was behaving in this manner. Now their mother tells them the car accidents Willy has been having, are in fact attempts at suicide. The boys agree to try to stay closer to home and start a business together. Biff decides to ask his former boss for a loan to help start the new business.

At the beginning of act two, Willy and Linda are full of hope for their family's future. Willy is going to talk to his boss, Howard, and try to change his job from that of traveling salesman to floor salesman in the store. They are also hopeful about Biff and Happy's future business venture. If Biff can receive the loan from his former employer, than it will mean a bright future for the boys. Biff at age 34, needs to settle down and make a career for himself, he sees that and so does his parents.

Willy tries to talk to Howard about the job change, but Howard tells him he just doesn't have a position open for him in the store. He needs Willy to keep selling to the clients in the New England area. Willy becomes angry with Howard and starts to yell at him. Howard after trying to calm Willy down, eventually has to fire him.

Biff is left waiting in his former boss, Bill Oliver's office for six hours and he only sees Bill, as he is leaving for the day. It is clear that Bill either doesn't remember Biff or doesn't want to speak to him. Biff, after all, did steal some basketballs from Bill's business. Biff in a pique of anger enters Bill's office and steals his pen. As he is making his escape from Bill's office he realizes he and Bill never did have a real relationship and he has made a mess of his life.

Biff and Happy have made plans to meet their father in a restaurant to celebrate the anticipated good news from the day. Instead, it is all bad news and Willy is not willing to accept the truth from Biff. The two boys meet some girls and leave Willy alone in the restaurant, which causes Willy to have another hallucination about a woman he had used to cheat on Linda.

At home, Linda is furious with the boys for leaving their father behind at the restaurant. She tells them it would be better if they left and never returned, because they causes so much stress for their father. Willy and Biff finally tell each other how they feel, which makes Willy understand that his son loves him. Willy decides the insurance money of twenty-five thousand dollars would benefit his family. He talks to Ben and decides to kill himself. Afterward, Linda has a hard time dealing with Willy's death. She cannot bring herself to cry, because she keeps on waiting for him to return from another business trip. She is sad, because finally the house is paid for and now she does not have a husband to share it with.

This play shows how false perceptions of ourselves and others can bring about the ruin of a person. If a life is based on a lie, then eventually the truth can be too much to endure.