BackgroundPrevious studies have shown that physical appearance perfectionism could play an important role in social physique anxiety; however, the moderating role of body compassion has not been studied. The current study aims to explore the moderating role of body compassion in the relationship between physical appearance perfectionism and social physique anxiety in undergraduate students.MethodsA sample of 418 undergraduates (n = 418; 217 female and 201 males) from three universities in Tehran, Iran completed online questionnaires measuring physical appearance perfectionism, body compassion and social physique anxiety.ResultsThe results of structural equation modeling showed that physical appearance perfectionism (β = 0.68,p< 0.001) positively predicted the social physique anxiety and body compassion negatively predicted (β = − .56,p< 0.001) the social physique anxiety in undergraduate students. A multi-group analysis showed that body compassion acted as a moderator between physical appearance perfectionism and social physique anxiety.ConclusionsThe results suggested that individuals with greater levels of physical appearance perfectionism are more likely to experience social physique anxiety. Also, the results suggested that individuals who were at a high level of the body-compassion group experienced lower levels of social physical anxiety if they also had high levels of physical appearance perfectionism. Therefore, body-compassion acted as a protective role in the relationship between physical appearance perfectionism and social physique anxiety.