Background: Obesity has become a significant public health issue and ranking sixth among causes of death worldwide, working adults have been identified as a high-risk group more exposed to the predictors of overweight and obesity than the general population. This study aimed to evaluate the effect of health belief model among Benha Telecom Egypt employees at high risk for obesity. Research design: A quasi-experimental design was utilized. Settings: This study was conducted at Benha Telecom Egypt. Sample: Convenience sample of 80 employees was included. Three tools were uses 1) A self-administered questionnaire to collect data about socio-demographic characteristics, knowledge, nutritional habits, healthy food and regular exercises, and the effects of obesity on employee lifestyle 2) The health belief model (HBM) sub-constructs 3) Anthropometric measurement. Results: Around fifth of employees were obese class1 (low risk) while more than one third was obese class II (moderate risk) and about two fifths were obese class III (high risk of obesity). There was a highly significant difference between employees' knowledge and their practices regarding obesity, healthy food, and exercises pre & post application of HBM. Conclusion: The implementation of health belief model significantly improved the employee's knowledge, nutritional habits and practices regarding obesity. There were positive high statistically significant correlations between employees ' total practices and health belief model. Recommendations: Routine screening for obesity, dieting, and other weight reduction methods should be a component of the continuing medical care provided by all health services. According to HBM, it's important to taken into consideration the advantages and disadvantages of changing health behavior because people are more inclined to take action when they perceive advantages than disadvantages.