Although several US studies report disappointingly low use rates of prophylactic antithrombotic therapy, a rate of 85% has been achieved in a large unselected population with cardiovascular disease. That fortunate population were members of the Oregon–southwest Washington region of Kaiser Permanente Northwest, a long-established not-for-profit, group-model health maintenance organization. As of mid-1999, aspirin was used by 72% of the subjects, and prescription agents (largely warfarin) by an additional 12%. Over 90% of the subjects recalled receiving education about aspirin and medical advice to use it. Participation in an integrated, prevention-oriented, computer-linked medical care system seems to facilitate the promotion of aspirin use. The steps that Kaiser Permanente Northwest took included developing and publicizing a guideline, maintaining a single comprehensive medical record, ensuring that hospitalized patients with cardiovascular disease were discharged with a prescription for aspirin, having nurse- and pharmacist-care managers promote aspirin use, and sending e-mail and letter messages to clinicians. After the study was completed, the health maintenance organization successfully promoted aspirin use in diabetes with a direct mailing to patients and dramatically increased medical documentation of aspirin use through alerts and routines embedded in its electronic medical record.