Mixed interspecific broods in hole nesting passerines occasionally occur as a by-product of competitive interactions for nest sites. Here, we report a rare case where such interactions led to a three species brood of Pied Flycatcher Ficedula hypoleuca, Blue Tit Cyanistes caeruleus and Great Tit Parus major nestlings that was successfully raised by a Great Tit pair. This occurred in an environment of relatively high temporal overlap in interspecific breeding. We suggest that such overlap may intensify interspecific competition between resident and migrant passerines that rely on similar resources.