To describe the results of 610 patients who underwent LEEP and evaluate factors related to a negative margin. A retrospective study of patients treated by LEEP at a colposcopy referral service in Campinas, Brazil, 2017-2019. Patients were referred to treat high-grade squamous intraepithelial lesion or adenocarcinoma in situ suspected by cytology and colposcopy (screen-and-treat) or by biopsy. Descriptive analysis was performed by frequencies as a function of the status of the margins (negative or positive). Factors associated with margin status were assessed by regression. The endocervical, ectocervical or both margins were negative in 82.4%, 75.7% and 65.9%, respectively. Age, sexual debut, parity, menopause status, smoking and hormonal contraception showed no difference in the proportion of negative margins. Both margins were negative in 66.1% of patients with transformation zone type(TZ) 1, 73.1% of TZ 2, and 54.7% of TZ 3 (p = 0.015). The endocervical negative margin was obtained in 78.0% of patients submitted to excision I (loop 10 mm) and 82.5% to excision II (loop 15 mm) (p = 0.016). Having the sexual debut at 18 years or older or being submitted to an excision type II doubled the chance of negative endocervical margin (1.98;1.04-3.77 and 1.95; 1.18-3.21, respectively). The proportion of negative endocervical margin was 78% in excision I and 86% in excision II. Sexual onset and excision type II increased the chance of obtaining a negative endocervical margin. © 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.