Abstract: Fish diet, feeding patterns and trophic interactions were studied according to season in a Sahelo-Soudanian man-made lake (Loumbila, Burkina Faso). Some food resources (zooplankton and benthic fauna) were also sampled. An examination of 425 non-empty stomachs belonging to 6 species showed that Auchenoglanis occidentalis, Clarias anguillaris and Schilbe intermedius varied their diets and feeding strategies from one season to another. These species adapt their feeding strategies to the seasonal food availability. The three other species (Brycinus nurse, Oreochromis niloticus and Tilapia zillii) showed constant specialisation in the same prey items. Diets overlaps were low during the wet season and Resource Breadths more or less higher. Thus diminution in food availability in the dry season appears to induce shortage of resources used by individuals and by whole populations, leading to an increased likelihood of competition between species. The changes in fishes feeding patterns within the year are an adaptive response to change in food availability and allow fish communities to make better use of available resources.