Instruction in electrocardiogram interpretation was provided for students by distributing complete electrocardiograms to them at the beginning of the week, for nine weeks, followed by analysis by an instructor at the end of the week. This problem-solving method required minimal instruction in theory and lecture time. Skills in interpretation were promoted by teaching recognition of specific electrocardiographic patterns and their differential diagnosis rather than electrocardiogram aberrations produced by particular diseases. Reinforcement was provided by the frequent repetition of similar electrocardiograms during the course. This course was evaluated by examining students before and after the course and comparing their results with those of general internists who took the same examination. The students significantly improved their mean score and scored significantly higher than the general internists.