Background: The substantial increase in youth obesity during the last two decades may have serious biological as well as behavioral/mental health consequences. Purpose: The purpose of this study was to assess how ecological factors and hence overall well-being were related to body mass index (BMI) in youths. Methods: Three BMI categories (normal; at risk for overweight; overweight) were calculated for 847 adolescents. Behavioral/mental associations were assessed for each category as well as between normal and at risk for overweight and overweight combined. Results: Significant associations existed between BMI and depression, suicidal ideation (combined data), use/abuse of drugs (combined data), race, age, parental marital status, and parental employment status. No significant associations were found between BMI and anxiety, use/abuse of alcohol, or gender. Discussion: The significant associations between BMI and depression/suicidal ideation suggest thorough screening with at-risk youths, especially those from ethnic minority groups and those experiencing changes in parental marital or employment status. Translation to Health Education Practice: It is imperative that health care professionals who work with weight problems attend to the ecological contexts of clients/patients. Data supports the need for collaboration between the medical and mental health communities in this regard. (Contains 7 tables.)