Objective: To estimate and compare the prevalence of overweight and obesity among self-identified lesbian, bisexual, and heterosexual college age women. Methods: A secondary analysis of the Spring 2006 National College Health Assessment was conducted with 31,500 female college students (aged 18 to 25 years) to compare body mass index (calculated from self-reported height and weight) among lesbian, bisexual and heterosexual college women. Results: Compared to heterosexuals female college students, lesbians and bisexual women were both significantly more likely to be overweight or obese. Lesbians were also less likely to be underweight compared to heterosexual college women. Conclusions: Self-identified lesbian and bisexual college women were more likely to be overweight or obese than their heterosexual counterparts. Health care professionals and educators should target these high-risk populations for obesity prevention programs. This study highlights the need for additional research examining the potential risk factors for overweight and obesity among young sexual minority women. (Contains 3 tables.)