This study had two objectives. The first was to assess the frequency and content of school-based anti-smoking education received by Romanian adolescents aged 14-15. Secondly, the study aimed to evaluate to what extent the implementation of a specific 5 lessons smoking prevention program influences the quality of anti-smoking school 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 55 participating classes from the seventh grade (28 in the control group and 27 in the experimental group). The experimental group participated in a school-based smoking prevention program consisting of 5 lessons. The control group beneficiated only in the standard anti-smoking education offered by their schools. Six months after 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 results showed a low exposure to anti-smoking school education among the Romanian adolescents. The implementation of the specific school-based smoking prevention program increased the exposure of Romanian adolescents to a higher number of lessons of smoking prevention and influenced positively the quality of these lessons. The study identified several gaps with respect to anti-smoking education in Romanian schools. It underlines the benefits of the implementation of a school based smoking prevention program with a clear structure, which contains appropriate educational messages and it is easy to implement.