Nineteen patients with isolated suprascapular entrapment neuropathy were seen between 1980 and 1986. A neurogenic cause and absence of other deficits were confirmed by electromyography. Electroneurographic tests were performed in 13 and demonstrated delayed conduction time and (or) reduction in stimulus response amplitude. In 16 patients there was an acute or chronic mechanical cause (direct pressure on the suprascapular nerve, forced dislocation of the shoulder blade). Two types of paralysis could be distinguished, an upper one affecting both the infra- and the supraspinatus muscles (12 patients), and a lower one involving only the infraspinatus muscle (4 patients). In two patients an inflammatory cause was considered likely, while in one the cause remained unclear. Restricting movement brought about an improvement in most patients, while in one the neurophysiological parameters improved after neurosurgical intervention, without complete clinical restoration.