A study was conducted on the epidemiology of camel trypanosomosis in Mauritania using 2073 camels of various ages in five regions (Trarza, Gorgol, Adrar, Hodh E1 Chargui, Nouakchott). The prevalence was determined through blood smear and serological tests: card agglutination test for trypanosomiasis (CATT) and immuno fluorescence antibody test (IFAT). The prevalence of the disease was 1.3% using blood smear examinations, 16.2% with CATT and 25.2% with IFAT. The following variations were observed: (1) Camels in Trarza had the highest prevalence; (2) Intraregion was a significant factor; (3) Animals that migrated to the south were more commonly infected than those in the north; and (4) Animals in the 5- to 10-yr age group had the highest prevalence. The study indicated that camel trypanosomosis was widespread in Mauritania, especially in the wooded areas near waterways in the south.