Carp, common bream, white bream, wild goldfish and roach are the most common large‐sized cyprinids in the littoral zone of Lake Balaton. Their cumulative average contribution to the littoral fish fauna is between 65.0% and 86.2% by weight but the relative abundance of each species differs by habitat. The diet of four of these five cyprinids significantly differed within and between all the three habitats examined The highest food‐niche overlap was detected between carp and white bream along the stony shoreline and in the reed grass stands (Horn's Index). However, high food‐niche overlaps were common in the open water areas, where all these species compete for similar food types. According to our results, the interspecific competition among cyprinids is expected to increase with the implementation of shoreline regulations and the destruction of the reed‐grass habitat.