Limited research exists on the effect of adolescents' affections on the success of cardiopulmonary resuscitation (CPR) training and the adolescents' decision-making skills and practices during an occurrence of cardiac arrest. We aimed to evaluate the effect of CPR training on the knowledge, behaviour and affections of students aged 16-17 years. A pretest-posttest randomised controlled trial was carried out with 115 tenth-grade students from western Turkey. The one group received basic life support (BLS) training, while the other group were given hands-only CPR (HOCPR) training. The study data were collected using a socio-demographic data form, the Positive and Negative Affect Scale (PANAS) and a CPR questionnaire. The median change in positive affect in the BLS group was -2.964; the median in the HOCPR group was -1.206. No significant difference was found between the groups. In the BLS group, the median change in negative affect was -3.649, and the median was 2.568 in the HOCPR group. The change in knowledge scores was higher in the HOCPR group. There was no difference between training methods in affections changes. Both methods reduced students' anxiety about CPR and provided a positive change in their thoughts about intervening in an occurrence.