From a series of 26 diabetics selected for combined pancreas and kidney transplantations 9 died before surgery was scheduled, one died after surgery and 4 rejected the transplants. The effect of pancreas or kidney transplantation or both on vibratory perception and thermal thresholds, various motor and sensory conduction parameters were studied in 9 of the remaining 12 patients. In 6 both the pancreatic and renal grafts were functioning, in 2 the pancreas was rejected, and in 1 the kidney. At an average follow-up of 41 months after surgery, the mean total score of clinical and electrophysiological improvement in 6 patients with successful combined transplantation was 5.5 +/- 1.6 compared with -4.3 +/- 2.5 in 3 patients with one surviving transplant (P < 0.001). Similarly, the average increase in nerve conduction velocity was 5.8 +/- 1.1 m/s in patients with two functioning grafts whereas it decreased 2.9 +/- 0.7 m/s in those with only one (P < 0.001). The quality of life was considered improved in patients with successful outcome of the two organ transplantations in contrast to the statements of those with only one.