ABSTRACT Introduction Colorectal cancer (CRC) was thought to be uncommon in black Sub Saharan Africa. High fibre diet, low incidences of adenomas and low social economic class are postulated to give protection against CRC. The past two decades have, seen a significant increase in incidence of a unique early onset, non-polypoid type of tumor affecting principally the rural population of generally low socio-economy status and whose diet differ significantly from that of similar patients from the developed countries. There are some similarities between Uganda tumors and MSI-H CRC found principally in Black Americans. Is the Uganda tumor therefore a unique form of CRC with some similarities to CRC found mainly among black Americans? Aim To provide basic epidemiologic, pathological and clinical data on CRC in Uganda and identify characteristics of this tumor which differ from those of similar patients from the developed countries. Methods The data presented is from a large data-base of colorectal cancer patients established at Mulago hospital in Jan. 2003. This data-base is being continuously upgraded by the research team in our colorectal Unit. Presently the database consists of 448 fully documented CRC cases. Results Of 448 clinically diagnosed CRC, 386 had confirmed histological diagnosis. CRC constituted 3.8% of all malignancies and 19.8% of all GIT malignancies. Incidence has doubled from 1.7% in 1983 and is higher than 2.5% average for the entire African continent. Mean age was 52.4yrs and M : F=1.2 :1. 68% of patients were rural peasants feeding on Bananas, Maize, Millet, Cassava, Yams, Vegetables and Tropical fruits with very low meat consumption and over 60% did not smoke or consume alcohol. Mean duration of symptoms was 9.4 months. 62.2% of tumors were rectal and 78% occurred on the left side. 70.6% of staged patients had Duke's C and D tumors. Only 12 tumors were found in co-existence with colonic adenomas, five of which were confirmed to have arisen from pre-existing adenomas and no synchronous tumors were diagnosed. Tumor resection was carried out in 38.3% of patients while 28% of patients declined surgery. Only 42% of patients were followed-up for mean duration of 8.6 months. Conclusion CRC in Uganda, is unique early-onset, non-polypoid form of CRC occurring mainly in young rural peasants, of low socio-economic status, eating unprocessed high-fibre, high-carbohydrate, low-protein and fat, traditional diet rich in vegetables and tropical fruits and is distinct from that found in patients from developed countries, who are generally 2 to 3 decades older, are mainly affluent and of generally high socio-economic status and whose diet is rich in processed animal fats and proteins and low in vegetable fibres. Whereas majority of tumors from the developed countries do arise from pre-existing adenomatous polyps, the Uganda tumors do not arise from such polyps. Uganda tumors therefore appear to be a unique form of CRC.