It is widely acknowledged that adolescent females are particularly at risk of low body esteem. Low body esteem is associated with poor mental health and other negative outcomes. Interventions to help raise body esteem could have a considerable impact, especially if the intervention is low cost, easy to implement, and scalable. We investigated the efficacy of an intervention where participants could choose their clothes to wear during a physical education lesson (PE). PE is a context associated with low body esteem, a finding that is particularly evident among females. We hypothesized that body esteem would improve with choice. To show that body esteem does not randomly change, we tested its stability when assessed in a test–retest design when completed in a classroom setting, hypothesizing that body esteem would be stable. Participants (n= 110; Age M = 14.9 years; SD = 0.68 years) completed a 14-item body esteem scale eight times: (a) wearing the school uniform in a classroom and (b) during a PE lesson on two occasions in each context within a week. This was repeated at the re-test, which was separated by a two-week gap. The intervention was implemented and students were given a choice of PE kit and could wear their own (non-designer) clothes. The findings indicate that the choice of PE kit intervention was associated with improved body esteem in a PE context but was stable in a classroom context, which we hypothesized to be stable. We argue that this low-cost and scalable intervention represents a useful starting point for helping to support females with low body esteem among a potentially vulnerable population.