The anterograde tracer, Phaseolus vulgaris-leucoagglutinin (PHA-L) was injected into the medial septum-diagonal band complex of the rat. When PHA-L was injected into the rostral part of the medial septum, labeled axon terminals were distributed largely in the dorsal hippocampus. After PHA-L injection into the caudal part of the medial septum or vertical limb of diagonal band of Broca, labeled terminals were observed predominantly in the ventral hippocampus.