Between 1987 and 1998, 470 patients visited the national clinic for obstetrical brachial plexus palsies at the Karolinska Hospital, Stockholm, Sweden. This study reports on 247 children examined at 5 years of age using a special protocol for testing the sensory and motor function of the hand. The children were distributed in various groups depending on the number of injured nerves, whether they had some muscle activity in their biceps or deltoid muscles at 3 months of age, and whether any operations with nerve reconstruction had been performed. The shoulder range of movement in C5–6 palsies was significantly better in the group which had been operated on (operated group), but otherwise there were no differences between children who had been operated on (non-operated group) and those who had not. A decrease in grip strength and bimanual function in level C5–6 palsies was found, though these roots should not innervate the distal hand. Outcome was not influenced by the number of avulsions in upper-plexus palsies or whether the operation took place before or after the age of 6 months. The group with extensive lesions (C5–Th1) had the most root avulsions, showing a correlation between increased avulsions and decreased hand function. This study does not support operating on children with no activity of the biceps and deltoid muscles at 3 months of age, as other authors have concluded. Rather, it favours waiting for a late recovery.