The thalamic innervation of the rat basolateral amygdaloid complex was studied with a combination of light- and electron microscopic techniques using anterogradely transported Phaseolus vulgaris-leucoagglutinin (PHA-L) as well as combined degeneration and single-section Golgi impregnation for the identification of thalamo-amygdaloid synaptic relations. The results indicated that the basolateral amygdaloid nucleus corresponds in several features to a cortical structure. Like all cortical areas, the basolateral amygdaloid nucleus is reciprocally related to other cortical regions as well as to the thalamus.