A retention study was implemented in Marshfield, Massachusetts in May 1974 in order to ascertain if cardiopulmonary resuscitation (CPR) skills could be retained by secondary school students who had 15 months previously received training in mouth to mouth resuscitation and cardiac compression. The retention study also addressed itself to the question whether a 28-minute "refresher" film on CPR skills prior to the test would serve to improve performance of CPR skills. (In the initial study, the students had been divided into two groups: those that received both didactic and practice sessions and those who received didactic training only.) All the initial practice group students (178 students who had received both didactic and practical CPR training) were divided equally into "film" and "no film" groups. A small sample of students (38) who had initially learned CPR skills from didactic materials only were also tested. These students were also divided into "film" and "no film" groups. Retention of continuous CPR skills, breaths anc compressions, showed very little loss. Retention of discrete CPR skills which included checking for breathing, opening the airway by tilting the head and lifting the neck, giving three quick breaths, feeling the pulse, and examining the pupil showed considerable loss of learning overtime. The film intervention did little to improve performance of CPR skills. No significant differences in performance were observed between "film" and "no film" groups. The findings of this study with respect to retention of continuous and discrete psychomotor sills closely parallel findings of the three-month retention study. In summary, this study would indicate that training of secondary students in CPR leads to good retention of essential skills. As indicated in the previous study, retention of the ancillary decision-making skills was not satisfactory. Methods for teaching these skills so that they will be retained over time need further development.