Background: To evaluate whether pretreatment carcinoembryonic antigen and carbohydrate antigen (CA)19-9 are useful predictors of survival in patients with stage IV rectal cancer who have undergone curative resection. Methods: In this retrospective study, data on 73 patients who had undergone curative resection of stage IV rectal cancer were reviewed. Associations between various clinicopathological factors and survival outcomes were analyzed. Results: According to univariate analysis, elevated pretreatment CA19-9 (p = 0.0028), R1 resection (p = 0.0318), and mucinous or poorly differentiated adenocarcinoma (p = 0.0228) were significantly associated with poor overall survival (OS), and lymph node metastasis (p = 0.0211) was significantly associated with poor disease-free survival (DFS). Multivariate analyses showed that elevated pretreatment serum CA19-9 concentration (hazard ratios [HR] 3.33; 95% CI 1.24-9.42; p = 0.0174) was an independent predictor for OS and lymph node metastasis (HR 2.26; 95% CI 1.15-4.82; p = 0.0164) was an independent predictor for DFS. Among 55 patients with recurrences after curative resection, the rate of complete resection of recurrences was significantly higher in patients with normal pretreatment CA19-9 than in those with elevated CA19-9 (p = 0.049). Post-recurrence survival was significantly worse in patients with elevated pretreatment CA19-9 than in those with normal CA19-9 (p = 0.0196). Conclusions: Pretreatment CA19-9 is good predictor of survival after curative resection of stage IV rectal cancer.