To assess the long-term evolution of diabetic polyneuropathy after a combined kidney-pancreas transplant, an electrophysiological study was performed in 20 diabetic patients before transplant, and 1 (n = 18), 2 (n = 16), 3 (n = 10) and 4 years (n = 5) at a later date. Motor and sensory scores were calculated for conduction velocity and amplitude to determine the physiopathological process. During evolution the scores were not found to be decreasing. Motor and sensory velocity scores were significantly improved (p less than 0.05) 1 and 2 years after the graft, when score values tended to stabilize. Motor and sensory amplitude scores, which are more sensitive for axonal loss assessment were slightly but not significantly improved.