Group B streptococci (GBS) have gained much attention in recent years as a cause of serious infection in the newborn. Traditionally two clinical syndromes have been defined as "early onset", with fulminant septicemia, pneumonia and meningitis, and "late onset", with a mild meningitis. More recently some previously unrecognized clinical presentations of GBS disease have been documented. These include asymptomatic bacteremia, septic arthritis, osteomyelitis, ethmoiditis with orbital cellulitis, pneumoniae with empyema, conjunctivitis. The literature to date reports 30 instances of osteomyelitis due to GBS. This report describes a forty days infant with a group B streptococcal osteomyelitis of the proximal humerus. Has been also emphasized the increased frequency and the benign clinical course of streptococcal osteomyelitis in the neonate.