Injections of small amounts of horseradish peroxidase (HRP) or HRP coupled with wheat germ agglutinin within the caudate nucleus in adult cats resulted in retrograde labeling of neurons within the globus pallidus and within the fibers of internal capsule near the globus pallidus. These triangular and fusiform neurons, measuring 27-30 micron, project topographically to the striatum. The morphology and the location of some of the labeled neurons in these cases resemble the acetylcholinesterase-positive neurons of the nucleus basalis magnocellularis described by other authors. The findings from this study support the existence of a projection from the globus pallidus and peripallidal region to the striatum in cats.