Between 1988 and 1994, 326 patients with colorectal cancers were treated at the Ibn Rochd Oncology Centre in Casablanca; 88 patients were less than 40 years old (27%). There were 79 males and nine females. A family history of colorectal cancer was noted in 5%. The most frequent symptoms were bleeding and rectal pain. The localisation of the tumour was the rectum in 70 cases. According to the anatomopathological profile, Dukes stages C and D were the most frequent and mucosal adenocarcinoma was noted in 24 cases. Seventy patients had surgery, associated with radiation therapy in 59 cases. Adjuvant chemotherapy was given in 44 cases and palliative treatment in 17 cases. Recurrence occurred in 14 cases and metastasis in other six cases. At five years, overall survival and disease-free survival rates were 24% and 17%, respectively. Worse prognostic factors were mucosal adenocarcinoma, poor differentiated adenocarcinoma and Dukes C and D stages.