Background and Objective: Adolescence obesity and overweight is one of the most common health problems in different countries; it is also considered a factor affecting the quality of life and health. Obesity prevention and treatment strategy have the highest priority in public health. This study aimed to determine the effect of education based on health belief model on improving eating behaviors and weight control in overweight and obese high school female students of Ahvaz city in 2014-2015.
Methods: This research is a pretest-posttest study with control group performed on 120 overweight and obese high school female students who were randomly assigned to two groups of control and test. The data collecting tool was the health belief model based and nutrition behaviors questionnaire that was completed twice, before and 3 months after the education. Educational intervention was performed in 6 sessions for the test group. Finally data was collected and analyzed by SPSS19 and by using paired t–test, independent t-test and Chi-square. 
Results: Before the intervention, the two groups had no significant difference in terms of demographic variables, mean scores of different structures of model and nutritional behavior. There were significant differences between test and control group in the levels of behavior, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived efficacy, cues to action and self – efficacy after the intervention (P<0.05). Though no significant difference was observed in the mean score of students’ BMI and weight in both test and control group (P>0.05). 
Conclusion: The findings of this study show the effect and efficiency of the health belief model in promoting nutritional behaviors and weight control of students.