The frontal lobes play a critical part in the control of human behavior. We review evidence from neuropsychology and functional brain imaging on the cognitive functions subserved by the frontal lobes in working memory, in the endogenous control of attention, in response selection, inhibition and response monitoring, and in responding to affective signals and reward-related aspects of the environment. Finally, we consider developmental disorders of cognitive function that may be accounted for in terms of the abnormal control of attention mediated by the frontal lobes.