A randomized prospective study was done to examine long-term cardiopulmonary resuscitation (CPR) cognitive and motor skills retention and to compare the "self-taught" modular course with the standard lecture course. Both cognitive and motor skills were tested at one-, two- and four-year intervals after the initial course. Approximately half the students in both the modular and standard lecture courses also took a refresher course after one year. While there was no significant difference (P greater than .05) in retention based on the method of teaching (modular vs lecture course), students who took the refresher course after one year performed significantly better (P less than .01) at the two-year interval. Results four years after the initial CPR course (three years after the refresher course) were uniformly poor in both groups. Only three of 104 students were able to meet American Heart Association standards for the performance of CPR. Refresher courses are vital if CPR is to be performed effectively and competently. They should be available on a continuing basis with self-taught courses providing a good alternative to the formal didactic course as a means of providing instruction.