We present the study of 20 pediatric patients with difficult controlled epilepsy in which we used clobazam as adjuvant anticonvulsant therapy between January 1986 and July 1990 at the outpatients neuropediatric facility of the Hospital General Base Cayetano Heredia and the private practice, with 6 to 45 months follow up. The mean age for the onset of the epilepsy was 22 months and the most frequent kind was the generalized epilepsy syndrome both secondary and idiopathic. It was obtained a significant decrease of seizures in 60% of the patients with a complete control in 35% of the total. It was found the best outcome in secondary generalized epilepsies Lennox-Gastaut and West types. It was found tolerance phenomenon in 25%, and psychotropic effect in three patients. We suggest the use of this 1,5 benzodiazepine drug in difficult controlled epilepsies in children of our region.