The purpose of this study is to survey a national sample of physicians to investigate the relationship among several variables related to physician characteristics and physician willingness to adopt clinical practice guidelines. Whether physician concerns about malpractice liability affect their willingness to adopt medical practice guidelines is of primary research interest. While it is widely believed that development and dissemination of medical practice guidelines will increase quality of care and reduce physician malpractice concerns, no research has been done on the question of how malpractice concerns themselves may affect a physician's decision to practice in accordance with guidelines. We hypothesize that fear of a malpractice lawsuit could affect physicians' decisions to adopt practice guidelines in two ways: (1) physicians whose medical opinion is in agreement with the content of a practice guideline for a particular patient may nevertheless refuse to follow the guideline if they feel legally vulnerable because of adverse side effects or complications associated with the guideline's suggested course of action; and, (2) physicians whose medical opinion is in disagreement with the content of a practice guideline for a particular patient may feel pressured to follow the guideline out of fear that deviation from a formally promulgated guideline may result in malpractice liability if the patient experiences an adverse consequence from the disease or condition addressed by the guideline. The results of the study should provide useful information for drafting, disseminating and improving acceptance of medical practice guidelines.