A BMI cutoff point at the 99th percentile for age and gender or at 40 kg/m(2) has been suggested for more aggressive treatment of adolescent obesity. The main objective of this study was to determine the proportion of adolescents eligible for weight loss surgery (WLS) based on various BMI cutoff points. Data was extracted from the electronic medical record database of an urban pediatric ambulatory care center over 4 years. National data were used to calculate BMI percentiles (Centers for Disease Control and Prevention (CDC), 2000). Eligibility for WLS was based on a BMI percentile criterion (>or=99th percentile) or the adult WLS cutoff point (>or=40 kg/m(2)). The sample consisted of 3,220 adolescents aged 12-17.9 years, of which 53% were female, 55% were of black race, and 17% of Hispanic ethnicity. Overall, 88 (3%) adolescents had a BMI >or=40 kg/m(2) and 236 (7%) had a BMI >or=99th percentile (P < 0.001). All adolescents with BMI >or=40 kg/m(2) had a BMI >or=99th percentile. A total of 159/2,007 (8%) of 12-14.9-year olds had a BMI >or=99th percentile compared with 77/1,213 (6%) 15-17.9-year olds (P = 0.10), whereas 43/2,007 (2%) of 12-14.9-year olds had a BMI >or=40 kg/m(2) compared with 45/1,213 (4%) 15-17.9-year olds (P = 0.003). In summary, a relatively large proportion of adolescents from a diverse urban population would qualify for WLS based on the percentile criterion. Fewer adolescents would be eligible based on the adult WLS criterion, and younger adolescents would be less likely to be eligible for WLS than older adolescents.