Monosymptomatic hypochondriacal psychoses are akin to paranoia. Although presenting with a variety of delusional complaints in individual cases, the condition appears to represent a relatively dis crete diagnostic entity. It is less rare than usually thought, but those afflicted frequently to to the physical specialties, whose treatment does not benefit them. It is important to recognize the illness, since there is tentative evidence that it may respond to treatment with pimozide.