The clinic-neurographic study of 33 patients with renal failure and polyneuropathy is reported. The patient's age ranged between 18 and 58 years-old; 24 were males and 9 female. All the patients had blood urea levels above 100 mg/dl. and creatinine levels above 5,0 mg/dl. Ten patients were maintained by repetitive haemodialysis twice a week; thirteen with weekly peritoneal dialysis; ten with conservative methods (controls). All the patients had motor nerve conduction velocities (VCNM) measured in the median, ulnar and peroneal nerves, at same time of the clinical avaliation. According to the intensity of the neuropathy the patients were divided in four groups. Decreased vibratory sense, cramps and distal hypoestesia for fine touch were the most frequent symptoms disclosed. The peroneal VCNM was decreased in 97,82% of the cases, followed by the median (84,78%) and ulnar (82.60%). The autrors did not found a significant alteration in the VCNM before and after dialysis, and between the kind of dialysis used (peritoneal and haemo-dialysis). In 7 patients followed for years, the VCNM was stable in 2, increased in 2 and decreased in 3, when they become stable, improved or worsened theirs symptoms. Secondary hyperparathyroidism developes in the 3 patients who worsened the symptoms and decreases theirs VCNM. The authors found the peroneal VCNM studies very usefull and was the one who gave more data regarding the evaluation and follow-up of the patients with uraemia, showing a tendency of the VCNM decreased with worsening of the clinical symptoms, without relationship with the kind of dialysis procedure (peritoneal or haemodialysis).