Cookie Monster's Circle Book is a storybook adaptation of the Sesame Street "Circles" song. Herry Monster sings the song on the opening two-page spread, accompanying himself on the banjo.

After that, Herry drives Cookie Monster to the amusement park, to find some circles -- but Cookie Monster eats the circles as fast as Herry can find them. He eats the coins they need for admission, all the pies in the pie-eating contest, the wheels on the circus parade wagons, the targets at the target shooting game, and the cymbals on the bandstand.

At the end of a frantic day, Herry is stuck with Cookie in the parking lot -- the monster has eaten all the tires off the car.