목적: The objective of this study was to determine the appropriate cutoff level of serum squamous cell carcinoma antigen (SCC-Ag) to diagnose recurrent cervical squamous cell carcinoma during post-treatment surveillance. 방법: Between January 2000 and July 2014, a total of 158 women with cervical squamous cell carcinoma were treated with radiotherapy with or without concurrent chemotherapy in our department. A total of 1550 serum squamous cell carcinoma antigen tests during post-treatment surveillance of the 158 patients were included in this retrospective study. 결과: During post-treatment surveillance, 53 patients have been diagnosed as recurrent cervical cancer based on biopsy or a radiological test showing progression of a lesion. Receiver operating characteristic curve (ROC) for serum SCC-Ag to diagnose recurrent cervical squamous cell carcinoma showed that the area under the ROC was 0.914 (95% confidence interval: 0.887 ~ 0.942, p-value < 0.001). The best cutoff value for serum SCC-Ag using Youden’s index was ≥2 ng/mL (sensitivity = 80.2%, Specificity = 94.6%). 결론: Serum SCC-Ag test during surveillance was helpful to detect recurrent cervical squamous cell carcinoma, and the best cutoff value was ≥2 ng/mL.