Frequency of atrial fibrillation (AF) in patients diagnosed with ischemic stroke. StudyDesign: Randomized control study. Place and Duration of Study: Department of Medicine, Mohammadi Teaching Hospital Peshawar, from March 12, 2020 to March 4, 2021. Methods: In this study a total of 180 patients were taken after taking informed consent meeting inclusion criteria from Department of Medicine, Mohammad Teaching Hospital Peshawar. The informed consent was taken from patients or attendants. Basic information like, age, gender and contact details were taken of all selected subjects. After basic clinical investigation, ECG was done for all patients with 24 hours of Ischemic stroke who presented to the selected setting. Atrial fibrillation was as per operational definition. On pre designed preform, data was collected from all patients. Results: The mean age of patients was 52.20±22.42 years with minimum and maximum age as 18 and 72 years. There were 129(72.7%) males. According to operational definition 61 (27.3%) cases had atrial fibrillation while other 180 (72.7%) cases did not have atrial fibrillation. The frequency of atrial fibrillation was statistically same when stratified for age), gender, smoking, obesity, hypertension, diabetes mellitus. Conclusion: The frequency of atrial fibrillation was seen in 55% of the cases having ischemic stroke. Hence if atrial fibrillation is diagnosed early then ischemic stroke can be prevented