This study had two primary purposes: to examine the effects of group and individual teaching by nurses in the workplace on 140 female office employees' health knowledge, beliefs, and practices regarding breast self-examination and to identify factors associated with frequency of practice. Skill in technique, confidence in the skill, and frequency of breast self-examination increased significantly with both teaching formats, but there were areas of technique that needed further improvement. Perceived susceptibility to breast cancer and perceived benefits of breast self-examination increased significantly only with individual teaching; knowledge was not increased with either teaching format.