Background: Cervical cancer is the third most common cancer in Brazil and has a high potential for prevention and cure. The prevalence of invasive and preinvasive disease in women with cytological diagnosis of high-grade lesion – cannot exclude microinvasion (HSIL-micro) is not known. Methods: This cross-sectional study used a cytology lab database to identify women with HSIL-micro and HSIL referred to two colposcopic units from June 2006 to December 2012. For each woman with HSIL-micro, four women with cytologic diagnosis of HSIL who met the inclusion criteria were identified. Data were obtained from review of medical records. Results: Forty-seven patients with report of HSIL-micro and 188 patients with report of HSIL were included. The final diagnoses revealed a frequency of preinvasive lesions of 31.9 % (15/47) and 59.6 % (112/188) in patients with HSIL-micro and HSIL, respectively, while the frequency of invasive disease was 63.8 % (30/47) and 11.7 % (22/188), respectively. The HSIL-micro group showed prevalence of preinvasive or invasive disease 6.5 times greater (95 % CI = 1.6-5.7) and, for invasive disease, 2.4 times greater (95 % CI = 1.7-3.6) than the HSIL group. Conclusion: Higher risk of preinvasive and invasive lesions in women with cytologic diagnosis of HSIL-micro reinforces recommendations for immediate investigation.