Accurate appraisal of one's own abilities is one metacognitive skill considered to be an important factor affecting learning and behavior in childhood. The present study measured self-appraisal accuracy in children using tasks of executive function, and investigated relations between self-appraisal and informant ratings of real-world behaviors measured by the BRIEF. We examined self-appraisal accuracy on fluency tasks in 91 children ages 10-17. More accurate self-appraisal was correlated with fewer informant ratings of real-world behavior problems in inhibition and shifting, independent of actual performance. Findings suggest that self-appraisal represents cognitive processes that are at least partially independent of other functions putatively dependent on the frontal lobes, and these self-appraisal-specific processes have unique implications for optimal daily function.