Objective: Previous researches suggested that psychiatric problems and stuttering may be associated with common neurophysiological reasons or because of the social and psychological difficulties caused by stuttering. The aim of this study was to evaluate comorbid psychiatric disorders in school age children with stuttering and to compare stuttering patients with and without psychiatric comorbidity in terms of age, gender and stuttering severity. Methods: This is a cross-sectional, retrospective study and the study was conducted with 89 children aged 6-12 years who were diagnosed as stuttering. Diagnosis of developmental stuttering was established by child psychiatrists based on DSM-5 childhood-onset speech fluency disorder (stuttering) diagnostic criteria. The Clinical Global Impression Scale was used to assess the severity of stuttering. The psychiatric evaluation of the participants was conducted with Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL). Results: The rate of comorbid psychiatric disorders in school-aged children with stuttering was 51.7%. The comorbid psychiatric disorders were attention deficit and hyperactivity disorder (30.3%), social anxiety disorder (12.4%) and specific learning disorder (4.5%). The participants were divided into two groups according to the presence or absence of psychiatric comorbidity and compared in terms of age, gender and stuttering severity. The results showed that psychiatric comorbidity was significantly higher in boys (56%) than girls (23%), and the mean age of those with psychiatric comorbidity (8.06) was significantly higher than those without psychiatric comorbidity (7.16). There was no significant difference between the groups in terms of stuttering severity. Discussion: The results of this study revealed that one of two children in school age children with stuttering had a comorbid psychiatric disorder. Considering the literature data emphasizing the negative effects of psychiatric comorbidity in stuttering especially on stuttering treatment, we think that determination of psychiatric comorbidity and interventions will provide important benefits for both professionals and patients.