Introduction. This study was carriedout in French Guiana, over ten years (1994–2003) by three institutions (SPV,FDGPC and CIRAD); it updates the current state of knowledge of Tephritidae(both Dacini and Toxotrypanini tribes) species present in this country. Materials and methods. The work was mainly conductedin inhabited areas (from the Brazilian border to the Surinameseborder) where cultivated fruit crops are located. Specimens wereobtained by adult trapping and fruit sampling in nearby orchardsand at the edge of the rainforest. Trapping was done consistentlyfor 10 years, while fruit sampling was a discontinuous activity.We present only the results for fruit sampling from three consecutive years(2001–2003) in which a total of 880 kg from 45 fruit species in22 plant families were collected. Results. Twenty-nineplant species from fourteen plant families were found to be hostsof twenty-one Anastrepha species and one Bactrocera species, Bactrocera carambolae Drew and Hancock. Duringthis period, no specimen of Ceratitis capitata (Wiedemann)was collected in traps or fruit samples. We registered the main fruittrees which were hosts for B. carambolae and Anastrepha spp. Fivehymenopterous parasitoid species were identified. Among them, Diachasmimorphalongicaudata (Ashmead) (Hymenoptera, Braconidae) is anexotic species and was introduced into French Guiana in collaborationwith Brazilian authorities (EMBRAPA) in 2000 and 2001 within the frameworkof a classical biological control program. Conclusion.Our data provide baseline information about the tephritid species ofeconomic importance present in French Guiana and assist in developing potentialfuture control programs of both the B. carambolae and Anastrepha species in the Amazon Basin. These preliminary resultsare discussed in the light of their implication for rainforest conservationefforts and also evolutionary relationships between fruit fliesand their hosts.