The main aim of health promotion and diseases prophylactic is a struggle with smoking, which is a well known factor in many disorders, i.e. malignant carcinomas, noncarcinomatous diseases of respiratory system and cardiovascular diseases. The aim of the study was the analysis of the knowledge level of smoking harm and its consequences in 1051 students of Wroclaw Medical University, Bialystok Medical University and the Public Higher Medical Professional School in Opole. The respondents answered to the anonymous, voluntary questionnaire. The little percentage of students in all centres gave correct answer to the subject of amount of carcinogens contained in the tobacco and the tobacco smoke still correct answers concerning concrete carcinogens were rare. Students aren't also convinced that the smoking can cause so strong psychophysical addiction, like taking drugs: heroine and cocaine. Majority polled is confirming that the smoking is a cause of the cancer of larynx, vascular diseases or chronic bronchitis, as well as an influence on a birth weight in newborn babies. Depending on the examined centre--convincing that smoking is the risk factor of bladder cancer isn't already so universal, the similar situation is taking place at examining the knowledge on the subject of association between smoking and osteoporosis. Admittedly the knowledge on the subject of nicotine substitute therapy isn't alien to students, they have the difficulty with correct giving available preparations on the Polish market. The knowledge of students is also scarce on the subject of changes in the total number of smokers in Poland.