PURPOSE: Advance directives have been available in parts of the United States for more than 20 years, but research shows that only a small percentage of adults (5-25%) have some form of written advance directive. The purose of this study was to examine the presence of advance directives among persons entering cardiac and pulmonary rehabilitation, and identify characteristics of persons most likely to have advance directives. METHODS: The sample consisted of 336 cardiac patients and 181 pulmonary patients who enrolled in the University of Alabama at Birmingham's Cardiopulmonary Rehabilitation Program between January 1996 and December 1999. As part of the initial program assessment, patients were asked two questions: (1) Do you have a living will? (2) Do you have any advance directives? For the purposes of this study, the two questions were combined to examine the presence of either a living will or other type of advance directive. RESULTS: Results indicate that 25% of both subgroups (cardiac and pulmonary patients) report having written advance directives. Logistic regression analysis indicates that among cardiac patients whites and older persons were more likely to have advance directives. Among pulmonary patients, females and whites were more likely to have advance directives. CONCLUSIONS: These results indicate that only a minority of cardiopulmonary rehabilitation patients have advance directives upon entry into the program, and that the prevalence differs among gender, racial, and age groups. Cardiac and pulmonary rehabilitation programs may be valuable sites for educating patients about advance directives and efforts by rehabilitation personnel may increase the prevalence of advance directives among patients.