Background: Adolescents constitute one fifth of the world population, the majority 84 percent are living in developing countries. If they do not meet their nutritional demands, they are at risk of becoming malnourished. Aim: The study was intended to assess adolescents' self-efficacy and perceived barriers toward healthy eating habits in Port Said city. Research design: This research employed a cross-sectional research design. Setting: The research was carried out at five preparatory schools chosen randomly from all five districts of Port Said city, Egypt. Sample: A multistage sampling technique was used in this study. Students from the two classes from first and second grade were chosen randomly from previous chosen schools, with a total number of 350 students. Tools: Three tools were used in this study, first tool: Dietary questionnaire, which divided into two parts: 1) Demographic characteristics of the studied students; 2) Dietary habits, second tool: Self-efficacy scale and third tool: Perceived barriers to healthy eating. Results: 51.7% of the studied students aged <12 years, 70.6% of the studied students are female and 38.3% were ranked the first according to birth order. There was statistical significant correlation between crowding index and perceived barriers. Conclusion: The majority of the studied students had good dietary habits; more than half of the studied students had moderate level of self-efficacy, besides there was statistical significant correlation between self-efficacy and perceived barriers. Recommendation: Develop customized nutritional interventions to raise adolescent awareness and encourage them to adopt healthy eating habits. Conduct health programs that target eating self-efficacy and improving dietary habits during early adolescence period.