The “Cheerleader Effect” (CE) describes how individuals’ faces are perceived as more attractive when presented in groups alongside similar faces, compared to alone. Other than faces, the CE emerges with full-bodies when individuals and groupmates are presented alongside similar body sizes and when rating perceived attractiveness. However, it remains unknown if the CE emerges with full-bodies and when rating perceived body sizes, or how differences in body size between individuals and groupmates impacts this effect. As such, this study examined (1) if ratings of perceived body size are impacted by individuals appearing alone or in groups, and (2) how this effect is impacted by differences in body sizes between individuals and groupmates. Nine women (Mage = 21.5 years) rated the perceived body size of 15 same-gender model images (3 models by 5 body sizes). Participants responded on a continuous scale from “very thin” to “very heavy” after models were presented alone or in groups with similar, thinner, or heavier groupmates of increasing body size differences. Women perceived individuals as thinner when presented alongside heavier (p<.05), but not similar, groupmates, compared to alone. As well, women perceived individuals as heavier when presented alongside thinner (p<.05), but not similar, groupmates, compared to alone. These effects became larger as the differences in body size between individuals and groupmates increased. Findings indicate that although ratings of perceived body size are impacted by groups, the effect depends on differences in body size between individuals and groupmates and is thus inconsistent with the CE.