Introduction: Heart rate variability have the potential to serve as a biomarker of SUDEP risk, allowing for increased counselling of patients and their families and serving as a valuable outcome measure for research aimed at developing drugs and therapies to reduce SUDEP risk. The sympathetic and parasympathetic modulatory activities of cardiac nerves result in a Holter test lasting less than 24 hours (a few minutes). Objective: for detection of heart rate variability and cardiac arrhythmias in epileptic children. Materials and methods: This cross-sectional study was carried out on 100 children with epilepsy. All patients were subjected to: history taking, full physical examination, echocardiography, 24 hours Holter, EEG, MRI brain, Standard 12-derivation ECG (including V4 R derivation). Results: There was a significant variability in HF, LF, LF/HF, RMSSD, SDNN and PNN50 among all time measurements throughout the day (P values <0.001). Heart rate variability was significantly worse in younger patients aged less than 10 years than others and was found comparable between males and females (P values > 0.05). Heart rate variability was significant in relation to EEG localization (All P<0.001) being worse in case of left temporal localization when compared to other types.