Abstract Background: Cortisol or 'stress hormone' is a product of hypothalamic-pituitary-adrenal axis. Its primary functions are to increase protein breakdown, inhibit glucose uptake and increase lipolysis. Aim of Study: To investigate the effect of high intensity interval training on plasma cortisol level in women with abdominal obesity. Subjects and Methods: Forty women with central obesity participated in this study. They were recruited from El Men-shawy general hospital. Their ages ranged from 30 to 40 year. They were randomly assigned into two groups; Group (A) included 30 women who underwent high intensity interval training (HIIT) in the form of running on treadmill for 4 minutes within 85%-95% of maximum heart rate with 4 minutes interval of active recovery for one month (3 sessions /week). Group (B) were 10 women who didn't perform any physical activity. International Physical Activity Questionnaire (IPAQ)was used to ensure that they didn't perform more than 150 minutes of any physical activity per week for last six months. Anthropometric measurements (weight, height, waist circumference waist hip ratio) and cortisol level were assessed before and after study. Results: Significant decrease in weight, body mass index (BMI), waist circumference (WC) and waist hip ratio (WHR) in and significant increase in cortisol level in group (A). In group (B) there was no significant difference in weight, BMI, WC and cortisol level while there was a significant increase in WHR. Conclusion: HIIT significantly improved weight, BMI, WC and WHR with significant increase in cortisol.