Résumé : Introduction: We investigated the impact of Cardio-Pulmonary Resuscitation (CPR) instruction by children on the attitude of people to perform bystander CPR. Methods: In 2012, children from primary and secondary school (age span 11-13 years) received a free individual CPR training package containing an inexpensive manikin and a training video. After a CPR training session by their class teacher, they were invited to teach their relatives and friends. After the training, the trainees of the children were invited to participate in a web survey, containing a test and questions about prior CPR training and about their attitude towards bystander CPR (BCPR) before and after the training. We measured the impact on the attitude to perform BCPR and the theoretical knowledge transfer by the children. Results: A total of 4012 training packages were distributed to 72 schools of which 55 class teachers subscribed their students (n=822) for the training programme for relatives and friends. After a validation procedure, 874 trainees of 290 children were included in the study. In comparison to trainees of secondary schoolchildren, trainees of primary schoolchildren scored better for the test as well as for a positive change of attitude towards future BCPR (. P<. 0.001). For every child-instructor 1.7 people changed their attitude towards BCPR positively. Conclusions: Instructing schoolchildren to teach their relatives and friends in Basic Life Support (BLS) led to a more positive attitude towards BCPR. The results were more positive with trainees from primary schoolchildren than with trainees from secondary schoolchildren.