The psychological effects of nonneurologic trauma on children are poorly recognized. We hypothesized that physical trauma in children, with or without head injury, would result in substantial and persistent psychological and behavioral abnormalities. Using a short telephone survey followed by a detailed behavioral checklist, we studied psychobehavioral dysfunction in children who had experienced trauma either with or without minor head injury (n = 40 each) as well as in a comparative group of children after emergency appendectomy (n = 80). Substantial behavioral disability was identified by the detailed checklist in 35% and 28% of children without and with head injury, respectively, but in none after appendectomy. Dysfunctions included phobias, major scholastic difficulties, rage attacks, and episodic depression that continued for a long period. Even in the 67% of children who eventually fully recovered, the duration of symptoms after the time of injury was an average of 19 months. Demographics, socioeconomic status, severity of injury, and length of hospitalization did not correlate with dysfunction, and these traumatized children's siblings had no reported history of trauma or psychological difficulties. Thus, parental opinion about behavioral dysfunction appears sensitive and specific and is therefore a useful screening index. These results suggest that injured children, even after minor trauma, may suffer substantial and long-lasting behavioral changes to a degree hitherto unrecognized.