To study the peptidergic innervation in cardiac adenocarcinoma, immunohistochemistry method was employed to examine the distribution of ten kinds of neuropeptide immuno reactive nerve fibers in human cardiac adenocarcinoma, which was surgically obtained, and their relationship with tumor cells. Substantial amount of many kinds of neuropeptides including GAL, Dyn, NPY immuno reactive nerve fibers were observed in the tumor. Most of them were closely in contact with tumor cells. It is possible that there is peptidergic innervation in cardiac adenocarcinoma.