Overweight and obesity are the fifth leading risk for global deaths. Obesity and the related health risks have been noted to be an epidemic problem worldwide , especially in developing countries. Aim: Application of health belief model among youth at high risk for obesity in Palestine (West Bank). Research design: A quasi-experimental design. Settings: The study was conducted at Faculty of Nursing /An-Najah National University, which located in Nablus and IBN Sina College for Health Sciences, West Bank-Palestine. Subjects: A purposive sample composed of 117 students, from both previous setting. Tools, three tools were used: First: A selfadministered questionnaire, it was composed of four parts, part one: socio-demographic data, part two: Assess university student's knowledge regarding obesity, nutritional habits, and its consequence. Part three: Assess university student's practices related to health belief regarding healthy food and regular exercises. Part 4: Assess the effects of obesity on university student's life style. Second tool: The HBM sub constructs which used in this study. Third tool: Anthropometric measurement to detect body mass index. Results: Revealed that less than half of youth were obesity class1, and more than one third were obesity class II. There was a highly significant difference between student's knowledge and their practices regarding obesity,healthy food, and exercises pre &post nursing intervention program Conclusion: This study concluded that, the application of health belief model among youth had a significant statistical relationship with improved knowledge and practices related to health belief of student at high risk for obesity. Recommendations: Conducting routine screening for obesity, dieting and other weight reduction practices as an integral part of the ongoing health care provided by all health services .HBM also suggests that the benefits and barriers of changing health behavior must be taken into consideration.