The aim was to examine the clinical features of Obsessive-Compulsive Disorder (OCD) in preschool and the effectiveness of aripiprazole with a standardized Cognitive-Behavioral Family Therapy (CBFT) in the treatment of preschoolers with OCD. Twelve preschool children, 36–72 months of age were diagnosed with OCD according to the Diagnostic and Statistical Manual of Mental Disorders, the Fifth Edition criteria by a fellowship-trained child and adolescent psychiatrist. They were evaluated with Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version and Childhood Yale-Brown Obsessive Compulsive Scale (CY-BOCS) at baseline, at the end of the 12th and 24th weeks of treatment. The baseline mean of total CY-BOCS score decreased from 33.67 to 13.83 at the 12th week and 5.58 at the end of the 24th week of treatment. Also, 66.7% of them had at least one psychiatric comorbidity. Overall, this study revealed the effect of aripiprazole with CBFT in preschool-aged children with OCD. Also, the presence of comorbidity that is seen frequently in preschoolers with OCD may complicate the treatment. Therefore, there is a need to increase awareness of OCD and its comorbidities in preschoolers to supply treatment at an early age.