Hyrcanian forests in the northern Alborz Mountains contain many resident and migrant passerines, but the ecological relationships of the species are obscure. We identified the ecological factors (forest structure, type, and topography) that could explain the distribution of the Eurasian Nuthatch (Sitta europaea) and its' habitat suitability in this region. Significant habitat parameters for presence-absence of Eurasian Nuthatch were height, diameter, stand, and type of trees. Our model successfully predicted the presence probability of nuthatches and that suitable habitats strongly depend on abundance of old trees, especially Oriental beach (Fagus orientalis) and European hornbeam (Carpinus betulus). These data suggest forest structure is the key factor in bird habitat use and suitability, and reveal the necessity of adaptive logging activities in Hyrcanian forests.