Changes in the flexion reflex of the tibialis anterior muscle of acute spinal cats were examined during conditioning, sensitization and habituation paradigms. Experimental animals were classically conditioned by pairing electrical stimulation of the saphenous nerve (CS) with stimulation of the superficial peroneal nerve (US). Recordings from these nerves assured known and constant stimulus inputs. The response observed was an increase in the magnitude of the reflex response to the CS over training. Habituation (CS only) and sensitization (CS and US presentations, unpaired) control animals exhibited no such reflex facilitation. The results of post-tetanic potentiation studies indicated that the intertrial intervals used were not a factor in the differences observed between experimental and control groups. The results give positive support to the concept of spinal conditioning and emphasize the potential of this model system for the study of neural correlates of learning.