Adolescents are a unique target group as optimal growth during this period is considered to be of main importance in maintaining good health thereafter. Calcium deficiency in early adolescence is one of the most common reported nutritional problems globally. Aim: To examine the effectiveness of nutrition intervention based on health belief model for promoting dietary calcium intake among adolescent girl students. Methods: Design: A quasi-experimental (study and control group) design. Subjects: Simple random sampling composed of 200 adolescent girl students aged 12-15 years. Setting: This study was conducted at four preparatory schools from rural and urban schools in Shebin El-Kom and El-Shohadaa districts at Menoufia Governorate, Egypt. Instruments: 1. A structured interview questionnaire that comprises socio-demographic data and environmental data about dietary calcium intake.2. Students' knowledge questionnaire related dietary calcium intake. 3. Students' practice habits questionnaire related dietary calcium intake. 4. Health belief model construct questionnaire related to dietary calcium intake. 5.Calcium rich food frequency questionnaire. Results: The findings of this study revealed a significant improvement in adolescent girls' awareness, and practice level related to dietary calcium intake in the study group as compared to the control group. Moreover, there was a significant increase in the mean total of dietary daily calcium consumption (mg) in the study group (1231.04±221.01) compared to 904.47±183.38 in the controls group. Besides, HBM structures mean score were significant higher including perceived benefits of calcium-rich foods consumption, susceptibility to the occurrence of diseases, risk resulting from the deficiency of calcium intake, and self-efficacy, while found a significant decrease in barriers to obtaining enough calcium in the study group compared to control group. Conclusion: Nutrition intervention based on HBM had a positive effect on promoting adolescent girls' awareness, and practice habits related to dietary calcium intake as well as promoting dietary daily calcium consumption. Recommendations: The need for establishing nutrition interventions based on HBM in schools to promote adolescent girls' calcium intakes, as well as emphasizing on parents and providing recommendations for enhancing calcium-rich food availability at home.