Background The long-term prognosis of patients with colon cancer is dependent on many factors. The aim of this retrospective study was to assess the long-term prognosis of patients with obstructing carcinoma of the right colon. Methods From 1981 to 1988, 256 patients at the Veterans General Hospital-Taipei who were status postcurative resection of right colon adenocarcinoma were classified as obstruction group (n = 35) or nonobstruction group (n = 221) as appropriate. Results Analysis revealed no differences in age, sex, tumor location, or stage (P >0.05) between the two groups. However, the overall and distant recurrence rates were significant higher in obstructed patients than in nonobstructed patients. Further, long-term crude and cancer-specific survival rates were significantly lower in obstructed patients when examining either overall patient outcome or stage-matched outcomes. Multivariate analysis demonstrated that obstruction and tumor stage were both independent prognostic factors. Conclusions Obstruction status was an independent prognostic factor for patients with right colon carcinoma. The long-term prognosis of patients with obstructing carcinoma of the right colon was poor.