In nine selected cases a primary nerve repair was done. In all these patients a special suture was used. Applying clinical and neurophysiological tests, regeneration of the motor and sensory nerve fibres was followed for two years. A remarkable difference in growth rates of sensory and motor nerve fibres was observed. The average rate of growth of sensory nerve fibres was 5 mm a day, and of motor nerve fibres it was 1.7 mm a day. At the end of a two years' interval after operation, good recovery from the initial muscular atrophy was observed in all but two cases. Function of previously denervated muscles was nearly normal. Discrimination of points 4-10 mm apart was possible. Normal terminal conduction times along motor nerve fibres were found in five cases. Slightly prolonged times were found in four. Calculated conduction velocities in sensory nerve fibres were half to three quarters of normal times. All patients resumed their previous occupations.