Between 1978 and 1989, some Plasmodium falciparum chloroquino-resistant (C.Q.R.) strains have been imported in all intertropical African countries. Evidence of sudden occurrence of C.Q.R. foci was obtained by some prophylactic or therapeutic failures, and culture of strains from non-immune travellers back in Europe or U.S.A., then by carrying out some field surveys. C.Q.R. heterogeneity is the rule in Africa, efficiency of other antimalarial drugs diminishes rapidly in the foci where C.Q.R. remains at high level, probably in relation with drug pressure. Non typical clinical manifestations raising of child death-rate death not avoidable by chloroquino-prophylaxis, confused therapeutic attitudes were all of them the main facts accompanying the occurrence of C.Q.R. in Africa. It is not possible nowadays to foresee the evolution of C.Q.R. situation and of its social consequences in low-immune African populations.