We evaluated the effectiveness and logistical practicality of use of a program consisting of computer-assisted instruction with interactive videodisc to teach residents in orthopaedic surgery the radiology of musculoskeletal injuries. Eleven residents (four in the fourth year of postgraduate training, five in the third year, one in the second year, and one whose level of training was not recorded) used the computer-videodisc program in a single session with no supervision. The residents took a pre-test and a post-test and also filled out a questionnaire on the efficacy and usefulness of this program compared with other educational materials. The eleven residents improved their scores from 56 +/- 8.6 per cent correct answers (mean and standard deviation) (range, 44 to 69 per cent correct answers) on the pre-test to 86 +/- 9.2 per cent correct answers (range, 69 to 100 per cent correct answers) on the post-test. All of the residents improved their scores, and the improvements were significant (p < 0.001; effect size, 3.57). The residents thought that the program increased their interest in the subject, and they preferred the computer-videodisc program to the use of actual radiographs, textbooks, videotapes, and slides and audiotapes for individual study. The residents reported no difficulty in using the program or the electronic equipment.