Inhibition was studied in 12 children who had had sustained as severe traumatic brain injury (TBI) at least 1 year earlier and in 15 control children. On the flanker task, which involved pressing a button corresponding to the direction of an arrow, the TBI group performed less accurately than controls under interference (flankers were incongruent with arrow) and go-no-go (adjacent stimulus signaled child to withhold response) conditions, but not neutral or facilitation (flankers were congruent) conditions. Response latency was related to age and task condition, but not group. Severe TBI in children may disrupt development of distributed networks mediating inhibition.