Objective To determine whether adjuvant chemotherapy improves the prognoses in women with stage IC1 epithelial ovarian cancer (EOC). Methods All eligible women diagnosed with stage IC1 EOC from 2003 to 2019 in Tongji Hospital were included. Patient characteristics, tumor features, surgical types, and chemotherapeutic treatments were collected. Kaplan-Meier analysis and Cox regression analysis were performed to evaluate progression-free survival (PFS) and overall survival (OS). Results Of the 140 patients (median age: 47 years old), 13 patients did not receive chemotherapy, and 127 received adjuvant chemotherapy. Kaplan-Meier analysis indicated that adjuvant chemotherapy offered no obvious improvements in PFS or OS. Subgroup analysis was conducted to adjust for the significant difference in incomplete staging surgery between the two groups, and chemotherapy still showed no benefit for survival. Cox regression analysis indicated that incomplete staging surgery was a risk factor for a worse PFS and that adjuvant chemotherapy remained unrelated to the prognosis. The patients were further divided based on the National Comprehensive Cancer Network recommendations: patients for whom observation is optional and chemotherapy would not improve the prognosis; and patients for whom chemotherapy is recommended. The results showed that postoperative chemotherapy had little correlation with survival. Conclusion Our study suggests that postoperative chemotherapy may be unnecessary for patients with stage IC1 EOC. According to our results, incomplete staging surgery is a significant risk factor for PFS.