The aim of this study was to develop, implement and evaluate the effectiveness of a behavior based, theory driven multi-component nutrition education Intervention promoting healthy eating among two (17 to 19 year old) Lebanese adolescent samples from contrasting socioeconomic statuses. The effects of the intervention were examined in a quasi-experimental control design trial among two hundred and nine adolescent males and females from Beirut, Lebanon: one hundred and ten belonged to a high socioeconomic status (HSES) population and ninety nine belonged to a low socioeconomic status (LSES) population of adolescents. There were four study groups: two intervention and two control. The intervention groups received twelve nutrition lessons, one hour each, involving class based teaching, print materials and activities delivered by a dietitian. Intervention Mapping protocol was applied and constructs from the Social Cognitive Theory were used for the development of the intervention. At baseline and after the intervention, food frequency questionnaires (FFQ) were administered and three 24-Hour Dietary Recalls were used to examine dietary practices and nutrient intakes while semistructured interviews were conducted to gain insight to underlying determinants of food choice. Quantitative data were analyzed using Mann Whitney U Test and Chi-Square analysis. Post intervention, adolescents in both the HSES and LSES intervention groups showed a significant improvement (p<0.05) in some dietary practices and nutrient intakes; however, the impact was higher in the HSES group. In both intervention groups, positive changes were observed in some personal determinants of food choice but none were noted for external factors. These results propose that the developed nutrition education intervention is a promising instrument to promote healthy eating among similar groups of Lebanese adolescents; however, further research is needed for interventions that specifically target LSES groups.