The study was carried out to promote a greater awareness of the potential for colorectal cancer in young adults under 40 years of age. During the 8 years between 1986 and 1993, 237 patients with adenocarcinoma of the colon and rectum were operated at the Uludag University Hospital. Of these 237 cases, 46 patients under 40 years old were reviewed retrospectively. They accounted for 19.4% of the total number of patients with carcinoma of the colon and rectum operated during the same period. Rectal bleeding was the most common presenting symptom. The mean duration of time from the onset of symptoms to diagnosis was 5.8 months. The rectosigmoid area was the most frequently involved site (80%). Seventy-six percent of the patients had Dukes' stage C or D tumors. Forty-eight percent of the tumors were either poorly differentiated or mucinous. The cumulative survival rate at 5 years was 43.4%. Patients under 40 years old with carcinoma of the colon and rectum are usually symptomatic and have advanced disease at the time of presentation. Although colorectal cancer is usually a disease of older patients it is becoming more common in younger populations.