Sexual dimorphism is described in the dentritic field pattern of Golgi-stained neurons from the dorsomedial preoptic area of adult golden hamsters (Mesocricetus auratus). Data were obtained through a mathematical reconstruction of dentritic densities of neurons sampled from this area in males and females. Males tended to have a central concentration, while females showed an irregular dendritic density distribution with concentrations dorsolateral, ventral and medial to the area of highest dentriic density in the males. These results suggest sex differences in the afferent inputs to neurons in the dorsomedial preoptic area which may be related to functional sexual dimorphism in physiology and behavior.