Background The present study aims to use two different kinds of filling materials, oxidized regenerated cellulose and gelatin sponge, to repair defects of breast-conserving surgery due to breast cancer, and compare the clinical efficacy, cosmetic effect and complication rate among groups. Methods A total of 125 patients, who had breast -conserving surgery due to breast cancer, were enrolled into the present study. Postoperative efficacy was assessed by a doctor and patient, according to the Harvard/NSABP/RTOG Breast Cosmetic Grading Scale. Results Among these patients, 41 patients received conventional breast-conserving surgery, and 84 patients received breast-conserving surgery plus filling implantation (41 patients in the oxidized regenerated cellulose group and 43 patients in the gelatin sponge group). All patients had small to medium sized breasts (cup size A and B). The average weight of tumor tissues was 56.61 +/- 11.57 g in the conventional breast-conserving surgery group, 58.41 +/- 8.53 g in the oxidized regenerated cellulose group, and 58.77 +/- 9.90 g in the gelatin sponge group. The difference in pathological factors, average operation time, length of stay and local infection rate was not statistically significant among the three groups. 18 patients in the oxidized regenerated cellulose group and 15 patients in the gelatin sponge group were evaluated to have a good cosmetic effect by the surgeon and patient, while 12 patients in the conventional breast-conserving surgery group were evaluated to be have good cosmetic effect by the surgeon and patient. The cosmetic effects in the oxidized regenerated cellulose group and gelatin sponge group were comparable, and these were superior to those in the conventional breast-conserving surgery group. Conclusion The use of oxidized regenerated cellulose and gelatin sponge is a feasible approach for defect repair after breast-conserving surgery.