Abstract Background Prophylactic uterine artery embolization (UAE) combined with subsequent curettage is suggested as an effective and minimally invasive treatment strategy for cesarean scar pregnancy (CSP) with a high bleeding risk. However, the timing of curettage after UAE remains to be studied. Thus, we aimed to identify the optimal time interval to perform curettage after UAE in patients with CSP. Methods We conducted a retrospective cohort study in a large medical center for women and children in Southwest China. CSP patients treated by UAE combined with subsequent curettage were included and grouped by the treatment time interval between these two procedures. The clinical outcomes among arms were compared by univariate and multivariable analysis. Results Our study included 314 CSP patients who received this combination treatment in our department from January 2014 to December 2019. The median time interval between UAE and curettage was 48 h, with a range of 12-168 h among all participants. Thirty-two patients (10.2%) experienced intraoperative hemorrhage (blood loss ≥200 mL). Intrauterine balloon tamponade was used in 17 cases (5.4%). In 14 cases (4.5%), the procedure was converted to laparoscopy (or laparotomy). In the cohort study, patients with longer treatment intervals had more intraoperative blood loss and a higher incidence of complications than those with shorter intervals (P 72 h had an adjusted odds ratio of 3.37 (95% confidence interval: 1.40-8.09). Conclusion We suggest that curettage not be delayed longer than 72 h after UAE in this combined treatment of CSP.