We sought to identify patient characteristics associated with cervical intraepithelial neoplasia (CIN) 3 in adolescents. A cross-sectional cohort study was done using a colposcopic database. Data collected included demographic and clinical information as well as cytologic and histologic results. Variables associated with CIN 3 in the univariable analysis (P ≤ .10) were included in a multivariable logistic regression model. Of 614 adolescents evaluated, 48 (8%; 95% confidence interval, 6-10%) had CIN 3. No cancers were detected. In the univariable analysis, parity, ≥ 4 lifetime male sexual partners, and a history of sexually transmitted infections were associated with an increased risk of CIN 3. In the final model, only ≥ 4 sexual partners (compared to <4; adjusted odds ratio, 3.66; 95% confidence interval, 1.26-10.61) was significantly associated with the finding of CIN 3. CIN 3 was infrequently encountered in adolescents, and those with multiple sexual partners were at increased risk for CIN 3.