&NA;Between 1960 and 1979, 37 patients, ranging in age from 18 to 40 years, were treated for colorectal cancer. Symptoms typical of colorectal malignancy had been present for an average of 10.4 months; a positive family history, previous colonic disease, or immunosuppression was present in 22 patients (59 per cent). Distribution of lesions was unusual in that only 40 per cent were within reach of the sigmoidoscope, and only 7.5 per cent could be palpated on rectal examination.Dukes' staging at diagnosis was improved in distribution to that reported in the adult population (51 per cent localized vs. 40.1 per cent). Histologic characteristics of the tumors were not unusual; however, incidence of poorly differentiated (18.9 per cent) and mucin‐producing (10.8 per cent) cancers was increased. Perineural invasion was associated with disseminated disease. Vascular invasion was associated with disseminated disease and poor prognosis. Overall fiver‐year survival was 56.8 per cent. Five‐year survival in 24 patients undergoing potentially curative resection increased to 70.8 per cent.Colorectal carcinoma in patients under 40 years of age is unusual, and delay in diagnosis is common. The distribution of lesions is more homogeneous than that seen in older patients, and high‐grade malignancies are more frequent. Survival data in this series are more favorable than those generally reported. Improved five‐year survival following potentially curative resection (70.8 per cent) stresses the need for early diagnosis and treatment