This final paper deals with the topic of teaching teenagers and maintaining discipline in EFL classes at Lower Secondary School. It is focuses on issues of establishing rules of conduct in the classroom, which lead to maintenance of discipline. It is divided into two parts: theory and methodology. The theory chapters include an explanation who teenagers are, not only about the word teenager but also the development of this part of our society. There is also the results of a survey carried out among teenagers at lower elementary school and grammar school about the characteristics of teachers . My students were also asked to write their opinion on what good teacher should or should not be. The methodology part focuses on strategies which can be used to maintain discipline including classroom management and basic discipline rules. The last chapter deals with solving discipline problems in the classroom of teenagers. All of these rules to maintain discipline have been born out by practical experience over the decade in which I have been teaching teenagers.