BACKGROUND The goal was to compare fissurectomy with mucosal advancement flap anoplasty to fissurectomy alone in the surgical treatment of anal fissure. METHODS This study included patients who underwent surgery in 2019 for solitary, idiopathic, non-infected, posterior anal fissure, after failure of medical treatment. The choice to perform advancement flap anoplasty was based on surgeon preference and did not depend on the fissure itself. The main endpoint was the time to relief of pain. RESULTS Of 599 fissurectomies performed during the study period, 226 patients (37.6% women, mean age 41.7±12.0 years old) underwent fissurectomy alone (n=182) or associated with advancement flap anoplasty (n=44). The two groups differed as to their sex ratio (33.5 vs. 54.5% women, P=0.01), body mass index (25.3±4.0 vs. 23.6±3.9, P=0.013) and Bristol score (3.2 vs. 3.4, P=0.038). Time to relief of pain, time to disappearance of bleeding and time to healing were 1.1 (0.5-2.3), 1.0 (0.5-2.1) and 2.0 (1.1-3.6) months, respectively. The rate of healing was 93.8% and the complication rate was 6.2%. The differences between the two groups for these outcomes were not statistically significant. The risk factors associated with absence of healing were age ≥ 40 years (Odds ratio (OR): 3.84; 95% CI, 1.12-17.68) and pre-surgical duration of fissure<35.6 weeks (OR: 6.54; 95% CI: 1.69-43.21). CONCLUSIONS Mucosal advancement flap anoplasty does not provide any added value to fissurectomy alone.