The use of MRI in clinical psychiatry is evaluated on the basis of over four years' experience. Of 931 psychiatric patients examined, 156 were found to manifest pathological cerebral conditions, a frequency of 17 per cent, as compared with 2 per cent (2/101) among apparently healthy controls. The occurrence of intracerebral lesions, with exclusively psychiatric symptoms, is illustrated with case reports. The importance is stressed of early examination with neurodiagnostic imaging techniques in cases of psychiatric disorders where any of the following symptoms or preliminary diagnoses are present: atypical psychiatric features, first episode psychosis, late onset depression, dementia, HIV and other infections in conjunction with psychiatric symptoms, hysteria, and alcohol or drug abuse. The findings suggest MRI to be a useful supplementary diagnostic tool for improving the care of the psychiatric patient, while relieving the burden both on the patient's family and on mental health care resources.