© 2022 Elsevier B.V.Objective: To evaluate the effectiveness and tolerability of clobazam therapy in the pediatric population in terms of seizure semiology, epileptic syndromes, and etiological subgroups. Methods: A retrospective cohort study was conducted consisting of 1710 epileptic children from eight centers in seven geographic regions of Turkey. The initial efficacy of clobazam therapy was evaluated after three months of treatment. The long-term effectiveness of the drug, overall seizure outcomes, and overall therapeutic outcomes were evaluated during 12 months of therapy. Results: Analysis of initial efficacy after the first three months of clobazam therapy showed that 320 (18.7 %) patients were seizure-free, 683 (39.9 %) had > 50 % seizure reductions, and 297 (17.4 %) had < 50 % seizure reductions. A positive response (seizure-free and >50 % seizure reduction) was determined for focal-onset (62.3 %) seizures, epileptic spasms (61.5 %), and generalized onset seisures (57.4). The highest positive response rate among the epileptıc syndromes was for self-limited epilepsy with centrotemporal spikes (SeLECTS). The highest negative response rate was for developmental and/or epileptic encephalopathies (DEEs). Magnetic resonance imaging (MRI) revealed a structural etiological diagnosis in 25.8 % of the cohort. A higher positive response rate was observed at MRI in patients with sequelae lesions than in those with congenital lesions. The seizure recurrence rate was higher in the patient group with epilepsy wıth genetic and metabolic causes, in individuals with more than one seizure type, and in those using three or more antiseizure drugs. Conclusions: This cohort study provides additional evidence that clobazam is an effective and well-tolerable drug with a high seizure-free rate (18.7 %), a significant seizure reduction rate (57.3 %), and with excellent overall therapeutic outcomes with a low seizure relapse rate and considerable reversible benefits in the pediatric population.