The documentary follows four salesmen as they travel across New England and southeast Florida, trying to sell large, expensive Bibles door-to-door in low-income neighborhoods, and attend a sales meeting in Chicago.

The film focuses in particular on salesman Paul Brennan, a middle-aged Irish-American Catholic from Jamaica Plain, Boston, who struggles to maintain his sales.

"[5] Elements of popular culture that appear as backdrops to the main story include the song "If I Were a Rich Man" from Fiddler on the Roof; a recorded orchestral performance of the Beatles' song "Yesterday"; The Tonight Show Starring Johnny Carson; the theme music of the television series Ben Casey; and televised boxing matches.

It is fact, photographed and recorded with extraordinarily mobile camera and sound equipment, and then edited and carefully shaped into a kind of cinematic mural of faces, words, motel rooms, parlors, kitchens, streets, television images, radio music—even weather.

[9] In late 1970, however, Pauline Kael of The New Yorker expressed her problems with the film in her negative review of the Maysles' subsequent documentary Gimme Shelter.

Kael even accuses the Maysles of "recruit[ing] Paul Brennan, who was in the roofing and siding business, to play a bible salesman.

Since The New Yorker's policy at the time prohibited the publication of such correspondence, the letter did not appear in print until 1996, when it was included in the appendix to the anthology Imagining Reality: The Faber Book of Documentary.

Aside from his own statement, this could easily have been checked out by contacting his employers, the Mid-American Bible Company.In 1992, Salesman was selected for the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant."