This study had two objectives. The first was to assess the frequency and content of school-based anti-smokingeducation received by Romanian adolescents aged 14-15. Secondly, the study aimed to evaluate to what extentthe implementation of a specific 5 lessons smoking prevention program influences the quality of anti-smokingschool education among Romanian adolescents. The investigation was performed in twenty schools from Cluj-Napoca, Romania, which were randomly assigned to the control and experimental conditions, resulting in 55participating classes from the seventh grade (28 in the control group and 27 in the experimental group). Theexperimental group participated in a school-based smoking prevention program consisting of 5 lessons. Thecontrol group beneficiated only in the standard anti-smoking education offered by their schools. Six monthsafter the program implementation, students from both experimental and control groups filled in a questionnaire,assessing several issues regarding their exposure to anti-smoking school education in the last year. The resultsshowed a low exposure to anti-smoking school education among the Romanian adolescents. The implementationof the specific school-based smoking prevention program increased the exposure of Romanian adolescents to ahigher number of lessons of smoking prevention and influenced positively the quality of these lessons. The studyidentified several gaps with respect to anti-smoking education in Romanian schools. It underlines the benefitsof the implementation of a school based smoking prevention program with a clear structure, which containsappropriate educational messages and it is easy to implement.