Body mage dissatisfaction (BID) is highly prevalent among adolescents. This thesis investigated psychological, social, and biological factors in adolescents from the Western Australian Pregnancy Cohort (Raine) Study. In girls, low global self-worth , higher body mass index (BMI), unhealthy family functioning, and teasing were related to BID. In boys, low athletic competence, maternal anxiety, teasing, and BMI were associated with BID. Early life family socioeconomic status was marginally related to BID. There were no significant associations between early life diet and BID. Pre-pregnancy maternal BMI was significantly related to BID. These findings can inform initiatives to foster healthy body image.