Abstract From June 2007 to June 2008, entomological, malacological and parasitological investigations were carried out in five villages in close proximity to a small dam of Raf-fierkro in Bouaké, central Côte-d'Ivoire. The objective of the study was to identify vectors and intermediate host snails of parasitic diseases related to water, and to assess the prevalence of malaria, schistosomiasis and soil-transmitted helminthiasis before dam construction. Mosquitoes were caught by human landing catches, snails were collected in water bodies, and microscopic analyses of blood, stool and urine samples were carried out. Two malaria vector species were identified:Anopheles gambiae and Anopheles funestus. The average infective rate of An. gambiae ranged between 3.1 and 4.5 %. The infective rate of An. funestus was 1 % in all sites. The entomological inoculation rate ranged between 343.1 and 427.1 infective bites per person per year (ib/p/y)for An. gambiae and between 14.6 and 40.1 ib/p/y for An. funestus. Three species of were found: Plasmodium falciparum (predominant species), Plasmodium ovale and Plasmodium malariae. There were no intermediate host snails of schistosomiasis with the exception of Biomphalaria pfeifferi,intermediate host snail of Schistosoma mansoni in Ahougui. The prevalence of urinary and intestinal schistosomiasis and soil-transmitted helminthiasis was low. Our studies revealed important transmission of malaria, with the presence of three plasmodial species, whereas schistosomiasis and soil-transmitted helminthiasis were present, but only at low frequencies.