Lesions of the brain restricted to the prefrontal area are not necessarily accompanied by overt (behavioural) neurological dysfunctions. Furthermore, some widely used neuropsychological tests are insensitive to prefrontal lesions. Therefore, the organic aetiology of emotional and cognitive alterations in behaviour in these cases is easily overlooked in clinical evaluation and misdiagnosis in terms of a functional psychiatric disturbance often follows. To direct attention to the possibility of brain damage, different syndromes and (behavioural) neurological dysfunctions are reviewed. Finally, the use of a number of psychometric tasks sensitive to prefrontal brain damage is suggested.