1. The progress of recovery after transposition of the ulnar nerve has been studied in forty-six patients with ulnar neuritis of traumatic or mechanical origin.

2. In assessing the results, the lesions were divided into three grades according to the severity of the neurological signs: Grade I, minimal lesions with no detectable motor weakness; Grade II, intermediate lesions; Grade III, severe lesions with paralysis of one or more of the ulnar intrinsic muscles.

3. The earliest and most constant result after operation was the relief of discomfort and ulnar paraesthesiae.

4. The degree of motor recovery varied according to the severity of the lesion at the time of the operation. In Grades I and II cases, all the muscles (with one exception) were acting against gravity and resistance at the final examination. In Grade III cases, the recovery was usually far from complete. Recovery of sensibility was uniformly good.

5. In a further six patients with persistent symptoms after transposition, relief was obtained by free mobilisation and placing the nerve deep to the flexor origin.