The purpose of the study was to identify mechano-receptors in the healthy, human posterior cruciate ligament. Ten ligaments from 10 fresh cadavers were studied with light microscopy. In addition to free nerve endings, two types of encapsulated mechanoreceptors were identified. They were located at the femoral and tibial attachments, and on the surface of the ligament. These findings support the hypothesis that the posterior cruciate ligament has an anatomic basis for a discriminating afferent flow of nerve impulses to the central nervous system. Therefore, its neural network may play a role in regulating the contraction of muscle groups that are fundamental to knee stability.