Cannery Row has a simple premise: Mack and his friends are trying to do something nice for their friend Doc, who has been nice to them without asking for reward. Mack hits on the idea that they should throw a thank-you party, and the entire community quickly becomes involved. Unfortunately, the party rages out of control, and Doc's lab and home are ruined—and Doc's mood. In an effort to return to Doc's good graces, Mack and the boys decide to throw another party—but make it work this time. A procession of linked vignettes describes the denizens' lives on Cannery Row. These constitute subplots that unfold concurrently with the main plot.
Steinbeck revisited these characters and this milieu nine years later in his novel Sweet Thursday.