The present study aimed to investigate developmental changes in executive functioning in children following moderate-to-severe frontal lobe injury, before or after the age of six. Their performances on a measure of general intelligence and on four tests of executive function were compared to those of non-injured controls. The study focused on both the final outcome, or mastery, of performance, as well as the process of task completion (i.e., rate and strategy). Results revealed that frontal lobe injury disrupts development of both executive and general intellectual skills. Further, while an earlier age at injury did not impact on the child's overall ability to carry out executive tasks, it was found to have a significant impact on the child's rate of performance. The impact of frontal lobe injury in childhood is by no means 'silent' and 'without functional significance', and an early age at injury does not necessarily imply 'better' recovery.