The frontal lobes of the brain have long been regarded as enigmatic in their function and perhaps should be considered even more so in states of dysfunction. Observed associations between structural lesions and psychiatric symptoms and the demonstration of disturbed function and morphology in the frontal lobes of individuals suffering from major psychiatric disorders have led to increased interest in this brain area. Psychiatrists have been particularly concerned with seeking the aetiogenesis of common diagnostic entities and this article attempts to synthesize the available facts. A brief overview of relevant biological data precedes a description of methods of neuropsychological testing and the clinical features arising from frontal lobe damage. A discussion of the role of the frontal lobes in some aspects of personality function follows. Neuropsychiatric features associated with known frontal lobe pathology are described, prefacing a discussion of those psychiatric conditions where an aetiological role for frontal lobe dysfunction has been proposed.