It is commonly known that protection of human health depends to greatest extent on knowledge and actions good or hazardous for it. Childhood and youth are periods of life when education is more likely to have the best results. The aim of my paper was evaluation of the level of teenagers' knowledge of prohealth behaviours. The survey, in accordance with the standardised interview method, was carried out among the group of 100 secondary school students in the Lublin region. As a result it was proved that the level of the students' knowledge of certain prohealth behaviours varies. Negligence in health education is confirmed by a considerable percentage of wrong answers to questions concerning physical activity, selected issues from hygiene and stress. Health awareness among teenagers is moulded mainly by mass media and peers. The majority of the respondents admit incomplete knowledge of the subject. Since the role of the family in health education is rather limited, and the school includes this issue in its teaching programme to small extent, it would be desirable to place "health education" among other school subjects.