Study Objective: To compare the outcomes of hysteroscopic management in women with a severe or nonsevere symptomatic cesarean scar defect (residual myometrium ≤3-mm vs >3-mm, respectively). Design: Retrospective cohort study. Setting: Gynecology department of a teaching hospital. Patients: Seventy-one women with an operative hysteroscopy for a symptomatic defect (49 with severe defects and 22 with nonsevere ones). Interventions: Operative hysteroscopy for cesarean scar defect in women with a severe defect (residual myometrium ≤3mm) and with nonsevere defect (residual myometrium >3-mm). Measurements: The main objective was to compare success rates between the 2 groups. The secondary objectives were the comparisons of (1) the number of women who required more than 1 procedure, (2) the rate of complications, (3) the number of subsequent pregnancies, and (4) the evolution of residual myometrium thickness between the groups. Main Results: The success rates were not significantly different between the groups (73.5% in the severe group and 63.6% in the nonsevere group [p = .40]). The number of women requiring more than 1 procedure was also similar, as were the rate of complications and the mean increase of myometrium thickness. The rate of subsequent pregnancies in women who were infertile was significantly higher in women with a severe defect (p = .04). Conclusion: The hysteroscopic approach seems to be a good way to manage cesarean scar defects even when the residual myometrium is thin. A prospective study is, however, necessary to confirm these findings.