Previous studies on colon cancer have noted rising incidence rates among young individuals and suggest that they may have more aggressive disease and worse 5-year survivals than their older counterparts. Our study uses a nationwide population-based cancer registry to analyze colon cancer presentations and outcomes in a young versus an older population. The records of patients with colon carcinoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) national cancer database (1991-1999). Two cohorts based on age at diagnosis (20-40 years, n = 1334 vs. 60-80 years, n = 46,457) were compared for patient and tumor characteristics, treatment, and 5-year cancer-specific survival. A multivariate Cox regression was performed to identify predictors of survival. The young group had a higher proportion of black and Hispanic patients than did the older group (p < 0.001). Young patients had less stage I or II disease, more stage III or IV disease (p < 0.001), and worse-grade (poorly differentiated or anaplastic) tumors (p < 0.001). The 5-year stage-specific survival was similar for stage I and III disease (p = NS) but was significantly better for young patients with stage II and IV disease (p < 0.01). Using a nationally representative cancer registry, we found that young colon cancer patients tend to have later-stage and higher-grade tumors. However, they have equivalent or better 5-year cancer-specific survival compared to older patients. This population-based finding contradicts prior single-institution reports.