SUMMARY Background: Given the improved knowledge of colonic carcinoma worldwide, it is becoming increasingly clear that there are perhaps distinct clinico-pathological, and probably molecular biological, differences between the high-incidence colorectal carcinoma (e.g. in Caucasians) and low-incidence disease (e.g. among black Africans). Whereas there are putative explanations, the bases for the observed differences have however not been well explored. An enduring impediment to this is the subsisting dearth of literature on the pathological characteristics of the disease as it is found among indigenous Africans. Our purpose for carrying out the study was to document the detailed pathological characteristics of the disease amongst our patients. Method: We retrospectively reviewed all cases of colorectal carcinomas seen in the Department of Morbid Anatomy and Forensic Medicine Obafemi Awolowo University Teaching hospitals complex from 1994 to 2003 for site of the lesion in each case, gross appearances of the tumour, the histological type and depth of invasion of the wall of the bowel. Staging was done using the Astler-Coller scheme. The presence or not of any other co-existing pathological changes in the adjoining mucosa was also noted. Results: A total of 115 cases of colorectal carcinoma were studied. Minimum age was 6 years. The mean age was 49.92 years; the peak age of incidence in this study was in the 41 to 50 years age groups, In this study the female to male ratio was about 1:1. The commonest site of this cancer was the rectum and the least occurred in the transverse colon. Over 95% of the cases seen in this study were polypoid masses. Non mucinous adenocarcinoma is the commonest histological presentation in this study. The mucinous adenocarcinoma account for 33.0%: we found that high grade and malignant mucinous tumours tend to occur in persons younger than 40 years. Such lesions have been associated with certain abnormal genetic alterations. The signet-ring cell carcinoma found in this study accounted for 3.5%. Similar to previous reports, all the signet-ring cell carcinoma cases seen in this study were of the poorly differentiated grade. Majority of the cases seen in this study were in Astler and Coller stage B2 and C2. We found only one case of associated schistosomiasis in this study. No case of the known premalignant lesions such as colonic polyposis or inflammatory bowel disease was found in this study. Conclusion: The remarkable rarity of well-known pre-malignant lesions such congenital familial colonic polyposis, adenomatous polyposis and inflammatory bowel disease in indigenous Africans makes the aetiopathogenesis of colorectal carcinomas yet an unexplored territory. Obviously, there is an urgent need to examine what probable roles the chronic inflammatory disorders such as schistosomiasis, and perhaps amoebiasis that are so common in many parts of Africa, might have. Probably, studies aimed at unravelling the molecular epidemiology of these tumours in Africans may yet provide the guiding light for such an exploration