Obsessive-compulsive disorder (OCD) is a psychiatric disorder which seen with recurrent obsessions and/ or compulsions, chronic, demonstrate periodic course and affects social and daily functions of the individual considerably. Studies shown that about half of the adult patients with a diagnosis of OCD; the onset of disease in childhood or adolescence. Early onset is associated with more severe symptoms, more comorbidities and bad course of disease. In cases with early-onset OCD may also occur psychotic symptoms; difficulties being experienced for the diagnosis, treatment and follow-up process of these cases. In this case report it has been studied the differential diagnosis of an OCD case mixed with early onset schizophrenia.