Despite the improvement in its prognosis in most Western countries, death from colon cancer is still a major problem. In a prospectively planned observation study, a large patient collective from a single institution in Austria was analyzed in terms of the surgical approach and factors influencing survival. A total of 696 patients with colonic carcinomas were admitted to our surgical department between January 1, 1984 and December 31, 1997. Radical surgery for localized tumors was consistently performed, including wide resection margins and complete removal of the regional lymph drainage zones. Clinical, histopathologic, and therapy-related factors were examined for their influence on long-term survival by means of univariate and multivariate analysis. The overall tumor resection rate was 99.3% (691/696); complete tumor removal (R0) was possible for 84.8% (590/696) of all patients. The overall postoperative hospital mortality rate was 3.2% (22/696), and it was 13% (7/556) for potentially curative resections. Five- and ten-year tumor-specific survival rates for stage I to III R0 resections were 83.8% and 78.8%, respectively. Adjuvant chemotherapy reduced tumor recurrence for stage III patients by 52.4%. The depth of tumor infiltration, lymph node status, and adjuvant chemotherapy were found to have an independent influence on survival as identified by the Cox models. In conclusion, a consistent radical surgical approach for potentially curative resected colonic cancer patients had survival rates that surpassed those of most published series without sacrificing low complication rates. In addition, adjuvant chemotherapy for stage III substantially improved survival.