Seventy-three children with slow recovery after obstetric lesion of the brachial plexus (biceps function returning after 3 months of age) and with relatively favourable neurophysiological investigation were followed until a mean age of 4.3 years. Predictions for C6 and C7 were confirmed in 92% and 96% of the cases, respectively. Predictions for C5 were confirmed in a smaller proportion of cases (78%). The inability to record nerve action potentials for C5, and the high frequency of secondary shoulder pathology are reasons for this. In all, 33 of the 73 children came to operation for medial rotation contracture (11) or posterior subluxation/dislocation (21); there was one case operated for inferior contracture.