Survival data on colo-rectal cancer patients from eleven comprehensive cancer centers were analyzed to examine the effect of race, socioeconomic status and other factors on the probability of survival. Complete data on variables of interest were available for 3617 colon cancer patients (2545 Caucasians and 1072 Blacks) and 1528 rectal cancer patients (1179 Caucasians and 349 Blacks). No significant difference was observed between the races with respect to either the follow-up time or the censoring pattern. For each site, Caucasian patients had a lower risk of death at any time point compared to Black patients, and this difference was maintained within categories of disease stage, sex, age and SES. The race effect was statistically significant in all multivariate models. Moreover, only race was significant in models that considered both race and SES. For either cancer, the racial difference in survival was most prominent for localized disease.