Atrial fibrillation (AF) is the most prevalent clinical arrhythmia found in clinical practice. Patients with AF have greater activity impairment which affects daily life, leading to a more sedentary lifestyle. Exercise training have various benefits for AF patients including improvements in frequency control, functional capability, activities of daily living and a lower resting pulse rate. Pedometers have recently gained recognition as a useful intervention in the promotion of physical activity (PA). Therefore, the aim of the study was to examine the effect of pedometer based aerobic walking program on steps count and resting heart rate among Patients with AF. Methods Quasi-experimental research design was carried out in outpatient cardiovascular clinic of the Specialized - Medical Hospital, at Mansoura University. Purposive sample of this study composed of 60 adult patients of both sexes who met inclusion criteria and divided alternatively into two equal groups study and experimental. Results the result shows significant improvement in step count by 2814 step \ day and drop in resting heart rate by 4 beat / minute in study group after program. Conclusion positive effect of pedometer based aerobic walking program on exercise parameters of AF patients.