Among adolescent girls, the health effects of frequent self-weighing are unclear. This study examines cross-sectional and longitudinal associations between frequency of self-weighing and body mass index (BMI), body satisfaction, weight control behaviors, and binge eating among a diverse population of adolescent girls. The study was conducted in the Minneapolis/St Paul, MN, metropolitan area between 2007 and 2009. The study population included 356 adolescent girls (mean age 15.7 years); 46.2% of the girls were overweight or obese and >75% were from a racial/ethnic minority group. Anthropometric and survey data were collected at baseline and at follow-up 9 months later. Hierarchical linear regression models were developed to test associations. Cross-sectionally, frequent self-weighing was associated with lower body satisfaction (P=0.034) and higher rates of healthy (P=0.002), unhealthy (P=0.016), and extreme (P=0.038) weight control behaviors. A quadratic association was found between frequency of self-weighing and binge eating, with girls who weighed themselves least and most frequently reporting the highest prevalences of binge eating (P=0.014). No association was observed between frequency of self-weighing and girls' BMI (P=0.111). Short-term longitudinal associations between baseline frequency of self-weighing and changes in body satisfaction, weight control behaviors, binge eating, or BMI were not observed. Findings suggest that among adolescent girls, frequent self-weighing is cross-sectionally associated with both healthy and potentially harmful unhealthy weight control behaviors, and does not contribute to weight loss over time. Adolescents should not be encouraged to engage in frequent self-weighing.