Forty-four children suspected of having been abused underwent Tc-99mdiphosphonate bone imaging at the time of initial presentation for treatment of trauma or burns. Twenty-six had negative scans. These patients never showed X-ray evidence of skeletal injury although ten were abuse victims. Two skull fractures were found on X-ray examination when the scan was normal.Initial roentgenograms confirmed the presence of bone injury in 11 children with positive scans. Five of seven children with positive scans and normal initial X-rays developed bone or periosteal lesions visible on later X-ray studies. One of the remaining two children was lost to further study and the other had a history suggesting a prior injury which might have healed sufficiently to yield normal X-rays.In the study of children suspected of having been physically abused, the skull should be X-rayed and a bone scan performed. The scan can identify which additional bony areas to study roentgenographically on the day of first medical encounter, and which areas to re-study should the initial roentgenograms appear normal.Bone scanning, using technetium 99mdiphosphonate is more sensitive than the roentgenographic skeletal survey in detecting early evidence of bone or periosteal injury.The evidence thus obtained is useful for protecting children from further abuse, either by court action or, more commonly, by effective counselling after the abuser's denial has been overcome.