Background: Cardiopulmonary resuscitation (CPR) is an essential part of first aid. Care is taken in the Czech Republic to educate adolescents about CPR. The aim of our study was to assess the actual level of theoretical knowledge about CPR and the effectiveness of an educational film developed with support from The National Project of Public Health department of the Czech Ministry of Health. Aims and methods: We developed a simple multiple-choice questionnaire with 17 questions with 4 possible answers. The questionnaire was distributed to secondary school students (exeluding those with a medical specialisation). The McNemara chi-square test of symmetry was ušed for statistical evaluation. Results: A total of 796 students from 26 classrooms participated, 784 (98.5 %) pairs of questionnaires could be ušed for evaluation. Initial knowledge of CPR was low (usually less than 30 % correct answers). There was a significant inerease (p<0.001) in the number of correct single answers as well as the total score after the film (a 37 % inerease in correct answers on average). Conclusion: our results demonstrate that in špite of the effort to inerease the level of knowledge about CPR in laymen, the actual level of knowledge is low and more frequent repetition of courses should be considered. The educational film is a useful tool for teaching of CPR.

        Key words: cardiopulmonary resuscitation, Basic Life Support, education