Objective To compare rates of cervical intraepithelial neoplasia grade 3 or greater (CIN3+) between women aged 21 to 24 and women aged 25 or older undergoing a see-and-treat strategy for high-grade squamous intraepithelial lesion (HSIL) cytology. Methods In this retrospective cohort study, women treated with a see-and-treat loop electrosurgical excisional procedure (LEEP) for HSIL cytology at our university-based colposcopy clinic between 2008 and 2013 were identified. Data collected included age, race, parity, smoking status, method of contraception, history of abnormal cytology, HIV status, and LEEP histology. Cohorts were compared using Pearson chi-squared test of association and Fisher exact test. Results Three hundred sixty-nine women were included in this analysis. The mean age was 30 (SD, 7.2; range, 21-56). Ninety-seven women (26.3%) were 21 to 24 years old. The rate of CIN3 in all women undergoing a see-and-treat LEEP for HSIL cytology was 65.9% (95% CI, 60.8-70.5). The rate of CIN 2 was 15.2% (95% CI, 11.9-19.2). Three women (1.1%) had invasive carcinoma. There was no difference in risk of CIN3+ in the young women compared with women aged 25 years or older (RR, 1.37; 95% CI, 0.92-2.02). Within this see-and-treat population, there was no correlation between presence of CIN3+ and race, smoking, contraception, or HIV status. Conclusions Most women undergoing see-and-treat for HSIL cytology will have CIN3 on final histology. In this large cohort, women aged 21 to 24 did not have lower rates of CIN3 compared with women aged 25 and older, suggesting that see-and-treat is still a valid treatment option for the prevention of invasive disease in young women.