Body dissatisfaction emerges at an early age in childhood. However, the unique experiences of young boys regarding muscularity have not been examined. Interview responses were collected from 101 6-year-old boys to examine muscularity- and thinness-oriented body dissatisfaction. Both muscularity- and thinness-oriented body dissatisfaction were evident; boys on average selected ideal figure sizes significantly more muscular and significantly thinner than current figures. In addition, a significantly greater proportion of boys wanted to be more muscular (32.6%) than less muscular (16.8%), and thinner (20.8%) rather than larger-fatter (8.9%). Further, boys perceived significantly greater rewards from muscularity than from thinness. Findings demonstrate that muscularity and thinness-oriented body dissatisfaction is present in a substantial proportion of young boys, although a greater proportion are dissatisfied with muscularity than with thinness, suggesting that examination of body image in young boys needs to focus on muscularity dimensions as well as thinness-fatness dimensions.