Twenty cases of shaken baby syndrome are reviewed to determine important signs, symptoms, physical findings, laboratory parameters, and prognosis. The signs and symptoms of this form of head trauma are nonspecific. The findings may mimic infection, intoxication, or metabolic abnormalities. Diagnosis depends on a high index of suspicion and the physical findings of a bulging fontanelle, head circumference greater than the 90th percentile, and retinal hemorrhage. The finding of bloody fluid from a lumbar or subdural tap is also highly suggestive. Computed cranial tomography findings confirm the diagnosis. The prognosis in the shaken baby syndrome is poor. Three of our 20 patients died and ten others sustained significant morbidity. The emergency physician must be alert to making this diagnosis in order to promptly institute therapy for acute head trauma.