The story is written in the first person as a series of journal entries, the narrator a woman whose physician husband has confined her to the upstairs bedroom of a house he has rented for the summer. She is forbidden from working, and has to hide her journal entries from him, so she can recuperate from what he calls a "temporary nervous depression—a slight hysterical tendency," a diagnosis common to women in that period. The windows of the room are barred, and there is a gate across the top of the stairs, allowing her husband to control her access to the rest of the house.
The story depicts the effect of confinement on the narrator's mental health, and her descent into psychosis. With nothing to stimulate her, she becomes obsessed by the pattern and color of the wallpaper. "It is the strangest yellow, that wall-paper! It makes me think of all the yellow things I ever saw — not beautiful ones like buttercups, but old foul, bad yellow things. But there is something else about that paper—the smell! ... The only thing I can think of that it is like is the color of the paper! A yellow smell."
In the end, she imagines there are women creeping around behind the patterns of the wallpaper, and comes to believe that she is one of them. She locks herself in the room, now the only place she feels safe, refusing to leave when the summer rental is up. "For outside you have to creep on the ground, and everything is green instead of yellow. But here I can creep smoothly on the floor, and my shoulder just fits in that long smooch around the wall, so I cannot lose my way."