This prospective study examined the physical, psychological, and socioeconomic effects of injuries on children and their immediate families. Ninety-two injured children admitted with minor (ISS less than 16) or major (ISS greater than or equal to 16) injuries were compared with a control group of 59 children admitted during the same period with acute appendicitis. The two populations were similar in mean age, sex ratio, parental age and work status, and number of siblings. The parents of the injured children had a lower level of education than those of the controls. Fifty-four percent of the minor injury patients and 71% of the major injury patients had persistent physical limitations at 12 months in contrast to none of the controls. Thirty-eight percent of minor injury patients had pre-existing behavioral disturbances compared with 14% of major injury patients and 10% of controls. Behavioral disturbances among major trauma patients showed a sharp rise to 41% at 12 months and tended to persist in cases with continuing physical limitations. The major injury patients and those with significant head injuries exhibited a decrease in academic performance; minor injury patients and those without head injury showed no change. Maternal malaise rose sharply to about 40% in both injury groups in contrast to 7% in the controls and was more common in the presence of persistent physical limitations. Only 73% of families in the major injury group had returned to normal family life compared with 87% of the minor injury group and 100% of controls.(ABSTRACT TRUNCATED AT 250 WORDS)