The aim of this research was to evaluate the knowledge that Galician schoolteachers from kindergarten, primary and secondary schools had on cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) after a training process comparing oblivion after one week (G1), after a month (G2) and after two months (G3). The sample was made up by 144 schoolteachers between 23 and 64 years old (M = 42.46 SD = 10.03), 100 (69.4%) women, and 44 (30.6%) men. For data collection an ad hoc questionnaire was used, also a mannequin QCPR Laerdal® and a Philips AED. The results show statistical significative differences between the average of correct answers on the first questionnaire, and the last one (p < .001) among all the studied dimensions and groups (G1, G2 and G3). Regarding the ability to carry out a CPR, only statistical significative differences were found regarding average depth (men vs women; p < .001). Regarding AED time of use there were not found statistical significative differences regarding the time to apply an effective discharge on different groups (p > .005; G1 = 61.98 seconds; G2 = 54.69 seconds; G3 = 56.68 seconds). After the formative programme about BLS, there is an increase of theoretical knowledge among the schoolteachers and it remains 2 months after the programme is given. Also, it happened the same regarding CPR skills and AED use program.