The acquisition of knowledge is presumed to be part of the coping process for women facing increased stress because of a breast cancer diagnosis. The purpose of this study was to evaluate the impact of an education program on the perceived adequacy of knowledge of patients with breast cancer receiving radiation therapy. Second, the intent was to investigate the patients' preferences regarding involvement in decision making, amount and type of information wanted, and preferred information-seeking activities.A priori quota sampling was planned to ensure that at least 20 subjects were recruited to each of 3 age categories, assumed to represent premenopausal, perimenopausal, and postmenopausal patients with breast cancer receiving radiation therapy. Subjects (N = 79) completed questionnaires before and after the evidence-based education program. The education consisted of a 20-minute interactive video (first session); individualized education, including technical procedures and self-care (second session); and a 1-hour class (third session). Individual teaching as required was provided afterward during radiation therapy.Significant increases in perceived adequacy of knowledge scores indicate that the program was effective, especially with information concerning disease and treatment for postmenopausal subjects. Subjects' participation in 7 of the information-seeking strategies suggests that many had actively sought information before undergoing radiation therapy. Preferences for information that may be indicative of individual coping patterns were similar for more than half of the subjects. The majority preferred as many details as possible, as much information as possible (good and bad), and to participate in decision making. However, not all subjects wanted complete information, except for the information on all side effects. Findings from this study suggest that individual patients' information preferences, priority information needs, and preferred information-seeking activities should be identified early and incorporated within educational programs to target resources and maximize the likelihood that positive patient outcomes will result.