Introduction: Intellectual disability (ID) is characterized by limitations in cognitive and adaptive functioning. The aim of this study is to examine sociodemographic characteristics, perinatal and childhood risk factors, and prevalence of psychiatric and biomedical comorbidities in children with ID. Methods: 260 patients with ID were included in the study (mean age: 8.42 [plus or minus] 3.59, 61% male, 75% mild ID). The Ankara Developmental Screening Inventory, the Wechsler Intelligence Scale for Children--Revised, and the Porteus Maze Test were used to assess the intelligence of the participants. An additional questionnaire was used to investigate their sociodemographic characteristics and birth, developmental, and medical histories. Results: Adverse perinatal/neonatal events (p < 0.001), biomedical comorbidities (p < 0.001) and seizure/convulsion history (p < 0.001) were strongly associated with the moderate-severe ID. The children with mild ID had more emotional-social deprivation (p = 0.022). Low socioeconomic situation, parental education, and teenage parenthood were risk factors for stimulus deficiency. While internalizing disorders were more common in those with mild ID and among girls, externalizing disorders were more common in those with moderate-severe ID and among boys. Conclusion: Interventions to perinatal/neonatal events may reduce the rate of moderate-severe ID. Evaluation of psychiatric and medical comorbidities and elimination of emotional-social deprivation should be fundamental components of the services offered to children with ID.