Acquired brachial-plexus neuropathy outside the immediate neonatal period is uncommon. Pseudopalsy of a limb, associated with osteomyelitis, is well recognized. Acquired brachial-plexus neuropathy as the initial presentation of osteomyelitis of the humerus in the neonatal period is described. Three infants presented at 3, 15, and 21 days respectively, with acute monoplegia consistent with brachial-plexus neuropathy. The infants were afebrile and generally well. Initial radiographs of the humerus were normal and blood cultures grew group-B streptococcus in all infants. Nerve conduction studies were consistent with brachial-plexus neuropathy. Following intravenous antibiotics, there was complete recovery in all infants. Osteomyelitis of the humerus should be considered in infants in whom there are no overt signs of sepsis and who present with brachial-plexus neuropathy. Early diagnosis and appropriate treatment should result in a complete neurological recovery.