Abstract Aims Evaluation of school pupils’ resuscitation performance after different types of training relative to the effects of training frequency (annually vs. biannually), starting age (10 vs. 13years) and facilitator (emergency physician vs. teacher). Methods Prospective longitudinal study investigating 433 pupils in training and control groups. Outcome criteria were chest compression depth, compression frequency, ventilation volume, ventilation frequency, self-image and theoretical knowledge. In the training groups, 251 pupils received training annually or biannually either from emergency physicians or CPR-trained teachers. The control group without any training consisted of 182 pupils. Results Improvements in training vs. control groups were observed in chest compression depth (38 vs. 24mm), compression frequency (74 vs. 42min−1), ventilation volume (734ml vs. 21ml) and ventilation frequency (9/min vs. 0/min). Numbers of correct answers in a written test improved by 20%, vs. 5% in the control group. Pupils starting at age 10 showed practical skills equivalent to those starting at age 13. Theoretical knowledge was better in older pupils. Self-confidence grew in the training groups. Neither more frequent training nor training by emergency physicians led to better performance among the pupils. Conclusions Pupils starting at age 10 are able to learn cardiopulmonary resuscitation with one annual training course only. After a 60-min CPR-training update, teachers are able to provide courses successfully. Early training reduces anxieties about making mistakes and markedly increases participants’ willingness to help. Courses almost doubled the confidence of pupils that what they had learned would enable them to save lives.