Objective: To evaluate the efficacy of suction and curettage (SC), with and without preprocessing, as a therapeutic strategy for cesarean scar pregnancy (CSP). Materials and methods: This retrospective study included 257 patients with CSP who received ultrasound-guided SC. Patients were grouped into the direct SC group (122 cases) and the preprocessing SC group (135 cases). The preprocessing SC group was further divided into four subgroups based on the different preprocessing methods (methotrexate injection, oral mifepristone, methotrexate with mifepristone, and uterine artery embolization/chemoembolization). Results: There was no significant difference in success rates between the preprocessing SC group and the direct SC group (94.07% vs. 97.54%, p > 0.05). The preprocessing SC group had increased intraoperative bleeding, longer operation times, prolonged hospital stays, and increased in-hospital costs (all p values < 0.05, compared with the direct SC group). Among the preprocessing SC group, the in-hospital cost for the uterine artery embolization/chemoembolization subgroup was significantly higher than that for the other subgroups. Conclusions: Preprocessing steps may do not increase the success rate of SC for CSP under certain conditions. Optimization of the preprocessing step requires further research. Content: The effectiveness of suction and curettage and other methods in treating cesarean scar pregnancy has been evaluated.