Purpose of investigation: The objective was to demonstrate the frequency of invasive cervical cancer or recurrent CIN in patients treated by a previous diagnosis of CIN 1-3. Methods: We analyzed 1,397 records colpocytologic and medical records. Recurrence of CIN or invasive neoplasia of the cervix after treatment of CIN was assessed. The chi-square test was used for statistical analysis (significance level set at less than 0.05). Results: We obtained 696 CIN 1, 244 CIN 2, 451 CIN 3, and six squamous carcinoma. Regarding patients who relapsed, there were 6/690 (0.9%) patients had an initial diagnosis of CIN 1, 8/236 (3.4%) CIN 2 and 21/430 (4.9%) CIN 3 (p < 0.0001). Comparing the frequency of relapse among each group, we found: CIN 1 vs CIN 2: p = 0.0073; CIN 1 vs CIN 3: p < 0.0001; CIN 2 vs CIN 3: p = 0.38. Conclusion: Although the number of relapses when comparing CIN 2 and CIN 3 were not significant, the data suggest that CIN 2 has lower recurrence rates, so these patients require more conservative treatment if a desire of future pregnancy is expressed.