Introduction The prognosis of survival for a person suffering from cardiac arrest increases when a layperson performs cardiopulmonary resuscitation (CPR) on-site. In Sweden, providing CPR training to people working in public places is considered a social benefit. Objective The aim of this study was to investigate the effect of a 3-hour CPR intervention for electricians. Methods Data were collected through an intervention by means of simulation and consisted of a pre-and post-assessment of the participants’ CPR performance. Results The results show a statistically significant improvement in ventilation (41%) and quality of compression (36%). Conclusion With short rehearsal training, the layperson can significantly improve the quality of CPR given. In a situation of cardiac arrest, this can be crucial for the patient’s survival and continued quality of life.