Introduction: Bioecological aspects of anophelines (Diptera: Culicidae) near areas under the direct infl uence of the hydroelectric plant reservoir of Serra da Mesa in Goiás, Brazil, were analyzed. Methods: Samples were collected at the surrounding dam area during the phases before and after reservoir impoundment. The infl uence of climatic and environmental factors on the occurrence of Anopheles darlingi, Anopheles albitarsis, Anopheles triannulatus, Anopheles oswaldoi and Anopheles evansae was assessed using Pearson’s correlations with indicators for richness and diversity as well as the index of species abundance (ISA) and the standardized index of species abundance (SISA). Results: The highest anopheline density occurred during the phase after fi lling the tank; however, no direct correlation with the climatic factors was observed during this stage. The reservoir formation determined the incidence of the anopheline species. An. darlingi was the predominant species (SISA = 1.00). Conclusions: The signifi cant difference (p < 0.05) observed between the species incidence during the different reservoir phases demonstrates the environmental effect of the reservoir on anophelines.