Background: Obsessive-compulsive disorder (OCD) is a heterogeneous disorder; therefore, there is a need for identifying more homogeneous subtypes. This study aimed to examine the clinical characteristics and comorbidity pattern of a large sample of pediatric OCD subjects, and to examine the impact of gender, age at onset, and lifetime tic disorders on the clinical presentation and comorbidity pattern. Methods: A total of 110 children and adolescents diagnosed with OCD were assessed using the Kiddle Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version (K-SADS-PL) for psychiatric comorbidity, and a clinical data form was filled out. The cutoff for differentiating prepubertal from adolescent onset was 11 years of age. Results: A total of 83.6% of the subjects had at least one comorbid psychiatric disorder. Oppositional defiant disorder and contamination/somatic obsessions were significantly higher in males (p=0.036 and p=0.03, respectively) than in females. Depressive disorders and religious obsessions were significantly higher in the adolescent-onset group (p=0.02, p=0.05, respectively) whereas disruptive behavior disorders were higher in the prepubertal-onset group (p=0.037). Disruptive behavior disorders were significantly more frequent in the tic (+) group than in tic (-) group (p=0.021). Conclusions: There were differences in the comorbidity pattern and clinical expression between genders and between prepubertal and adolescent-onset cases. Findings of this study supported the introduction of tic-related OCD as a specifier in Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5), and the necessity of a detailed assessment of other psychiatric disorders in youth with OCD.