Deep thrombosis of limbs are unknown in Africa South of the Sahara. Looking for their etiological factors, the authors reviewed 82 cases admitted with an undisputable diagnosis of thrombosis. They underline the coming in of the disease which appears to strike two targets populations female in strong genital activity and males between 40 and 60 years of age. The authors are of opinion that etiological factors are similar to those described in the literature but they underline some peculiarities. Anemia, mainly because of iron deficiency (30.5 p.c.) gyneco-obstetrical context with oral contraception (26.8 p.c.) dysmetabolism (19.5 p.c.) heredity (15 p.c.) and infections (14.5 p.c.) are on the top of etiological factors. Then we have congestive cardiopathies (9.7 p.c.) digestive lesions (6.1 p.c.) and neoplasiae, hemoglobinopathies, quite frequent in the region as well as surgical context without preventive anticoagulants (7.3 p.c.) do not seen to play a significant role: they start again the discussion about the natural protection of Black African against thrombo-embolic diseases. Finally, they point out the interest of antithrombine III and proteins C and S tests in any known causal factor.