Familial aggregation of colorectal cancer occurs even among sporadic cases that are not part of defined genetic syndromes. First-degree relatives of patients with "sporadic" colorectal cancer have a three- to fourfold increased risk of the same cancer. The aim of the present study is to investigate the relationship between a first-degree family history of colorectal cancer and the pathological and clinical features of the tumor (site, Dukes' stage, age at diagnosis, sex, and patient survival). Four hundred and sixty-one patients with colorectal cancer were evaluated (250 males and 211 females) and information obtained on their family history of cancer. Sex, age, and stage of disease were the only parameters that correlated significantly with survival. No relationship between family history of colorectal cancer and the prognostic variables was observed.