Monosymptomatic hypochondriacal psychosis (MHP) is a form of psychosis characterized by the delusional idea that there is a serious problem in the skin or other body parts. Because MHP patients believe that their complaint is dermatological, not psychiatric, they often admit to several other medical disciplines before coming to a psychiatry clinic. This leads to a series of time-consuming examinations and treatment interventions. In this case report, we emphasize the importance of diagnosing the illness correctly and referring the patient to a psychiatrist. The patient presented in this report has been treated with a new generation neuroleptic, olanzapine. This treatment has led to complete resolution of delusional symptoms. Therefore, we conclude that knowing that MHP is a psychiatric illness allows early establishment of diagnosis and successful treatment.