Franny and Zooey features two siblings, Franny and Zooey Glass, each in their own narrative. Franny, a short story, unfolds in an unnamed college town where Franny, an undergraduate, grapples with her disillusionment towards the perceived selfishness and inauthenticity in her social environment.

Zooey, a novella, delves into the life of Zooey Glass, Franny's brother, as he attempts to aid his sister through a spiritual and existential crisis within the confines of their parents' Manhattan home. Their mother, Bessie, is deeply concerned for Franny's well-being as Zooey offers what he believes to be brotherly love, understanding, and wise counsel.

J.D. Salinger describes these works as early and critical contributions to a series of narratives about the Glass family, a group of settlers in twentieth-century New York. Salinger expresses his dedication to the long-term project and his intent to complete it with care and skill.