Electrical status epilepticus during sleep (ESES) is a childhood-onset epileptic encephalopathy characterized by epilepsy, cognitive regression, and prominent activation of epileptic form activity during non-rapid eye movement (NREM) sleep. The current treatment plan is based on uncontrolled studies and case series, with a primary focus on the use of traditional antiepileptic drugs, hormonal therapies, and other therapies. It is suggested that earlier diagnosis and intervention may preserve neurocognitive development. The study's objective was to evaluate characteristics, treatment and outcome of children with electrical status epilepticus in slow wave sleep (ESES). This study was an open label uncontrolled study that included 50 patients (33males and 17 females) who were diagnosed as ESES, presented with convulsions and cognitive deficits. Their ages range from 2to15 years, from January 2018 until December 2020.The characteristics, outcome and treatment patterns of these children were analysed. Our results showed that the mean age of the included patients is 6.19years±2.80SD. The mean age of neurocognitive regression was 4.48 years±2.83 SD, hyperactivity, speech regression and global developmental regression were the most prevalent types of regression experienced by these patients (23.5%, 26.4%, 23.5% respectively). Patients with generalized seizures were 78%, while 22% had focal seizures. Steroids were highly significant in lowering the SWI of these patients and improving the IQ (P-value <0.001) than non-steroids. After treatment, the SWI of patients with abnormal neuroimaging was significantly higher than those with normal neuroimaging (P-value of 0.001). Our study revealed that children with ESES, presented with neurocognitive regression, seizures, and had a decrease in SWI after treatment with steroids which was strongly associated with an increase in intelligence quotient (IQ), but not with a significant improvement in behaviour (hyperactivity or inattention). Steroid treatment was more effective than other treatment patterns in improving SWI, IQ, and convulsions.