This study examined changes in family functioning and predictors of family outcome during the year following traumatic brain injury (TBI). The families of 94 children with TBI (mild = 50, moderate = 25, severe = 19), ages six to 15, were consecutively enrolled from two regional medical centers. Family interview ratings and standard measures of family and child functioning were completed three weeks after injury (measuring preinjury status), as well as three and 12 months. Two-thirds of families had moderate to good preinjury global functioning and coping resources, but more than half exhibited high levels of stress and at-risk family relationships. No significant preinjury differences by injury severity were seen on any measure. Whereas few changes in family functioning were observed over the year in the mild or moderate groups, greater deterioration occurred in the severe group. From one third to one half noted moderate to severe strain in 13 problem areas often seen in individuals with TBI. Preinjury family global functioning, however, was more strongly predictive of 12-month family functioning (R2 = .38 to .68) than was injury severity (R2 = .05 to .09). In four out of five outcome areas assessed at 12 months, preinjury status in each area was the strongest single predictor. Preinjury coping was the best predictor of stress. Families at risk can be identified and need ongoing support for optimal functioning.