As part of the Sudden Death Research Project at Stanford University School of Medicine, we have performed systematic neurologic examination of 41 near miss infants, 7 normal siblings of babies who died a sudden infant death, and 21 normal control infants. Many infants were examined longitudinally until 2 years of age. We found that near miss infants under 3 months of age had consistent abnormalities of muscle tone, particularly shoulder hypotonia. These abnormalities disappeared with maturation, but only 60% of older infants who had suffered near miss episodes of neurologically and developmentally normal. In addition, only one of the seven apparently normal siblings had an entirely normal neurologic examination when first seen. Thus, infants who present with near miss episodes may have an underlying central nervous system abnormality or may acquire some abnormality as a result of the episode.