This study compared private speech of children with ADHD and normal controls during problem solving and inhibition tasks. Thirty-two children (16 children with ADHD and 16 matched controls) aged 6-11 years participated. Consistent with previous studies, children with ADHD produced more task-irrelevant and task-relevant external private speech than control children during problem-solving tasks, but did not differ in their use of task-relevant internal private speech. During the inhibition/attention task (Continuous Performance Test-II), children with ADHD produced more task-relevant external and more task-relevant internal private speech, suggesting that they may have employed a less mature strategy to aid in self-regulation. The educational implications of the current study are that there should be an increased awareness of the developmental nature and functional significance of private speech and how private speech usage may differ in children with ADHD.