OBJECTIVE: It is clear that uterine carcinosarcomas and uterine papillary serous carcinomas (UPSC) have an adverse impact on outcome, but whether carcinosarcomas are worse than UPSC is unclear. The purpose of this study is to compare the pathology, survival, and disease recurrence of patients with carcinosarcomas to patients with UPSC. METHODS: The medical records of patients diagnosed with carcinosarcomas and UPSC between 1996 and 2009 at Samsung Medical Center were retrospectively analyzed. Information from pathology reports, site of relapse, time to recurrence, and death was obtained. The survival analysis was performed using the Kaplan-Meier method. RESULTS: Thirty seven patients with carcinosarcomas and 38 patients with UPSC were identified during the study period. There was no significant difference in clinical characteristics including age, body mass index, proportion with advanced stage disease, rate of optimal debulking, and adjuvant treatment used. In addition, the pathology showed no significant difference in tumor size, myometrial involvement, lymphovascular invasion, peritoneal cytology, cervical invasion, and lymph node involvement. Patients with carcinosarcomas had similar patterns of relapse as the patients with UPSC. There was no difference in the progression-free and overall survival between the carcinosarcomas and UPSC patients (p=0.804 and p=0.651, respectively). CONCLUSION: Patients with carcinosarcomas had similar clinicopathological features compared to the patients with UPSC.