Study of malaria pattern in French Guyana from 121.175 parasitological data collected from 1970 to 1979. -- General incidence is moderate (6,4 p. 1.000) and the mean plasmodial index is 2,7 p. 100. These paludometric data have much increased in 1973 (9,7 p. 1.000 and 5 p. 100) and 1979 (10,8 p. 1.000 and 4 p. 100). This is the consequence of two convergent factors both strengthening vectors activity: a flow of malaria infested immigrants and meteorologic conditions (lengthy drought). Plasmodial species involved are P. falciparum (84 p. 100) and P. vivax (15 p. 100), P. malariae having just a negligible role. However, it must be noted that from 1977, P. vivax, already prevalent in Oyapok, seems to become more frequently rated. -- True autochtonous malaria is localized in border areas; exchanges from both sides of the river are frequent and call for a regional coordination control. A part of these permanently active micro-foci, periodic rises observed are related, in almost all cases, to the arrival of malaria infested migrants. This is specially obvious in Cayenne Island where a sanitary control of migrants from endemic areas should be considered. -- A. (N.) darlingi is in French Guyana the almost sole vector, except for Upper-Oyapok where A. (K.) neivai is responsible for a malaria caused by Bromeliaceae. In exceptional conditions and localized foci A. (N.) braziliensis and less often A. (N.) aquasalis may be effective vectors. -- Anti-vector measures require an increased control at preimaginal stade. This public-health additional option calls for an integrated control: Cayenne Island conditions are assembled to design and evaluate a model.