The purpose of this national study was to determine advocacy activities and level of involvement of health commissioners regarding public policy. Benefits, barriers, and perceived outcomes of advocacy efforts were also explored. A previously validated (Holtrop et al., Am J Health Behav 24(2):132-142, 2000) four-page survey was mailed to 700 health commissioners, who were randomly selected from the National Association of County and City Health Officials (NACCHO) database. A three-wave mailing was performed which yielded a 50% response rate. Of these respondents, the majority (70%) were female and (88%) Caucasian. Overall, 31% of health commissioners reported being involved in influencing public policy in the last 4 years. The most common reported activities engaged in by health commissioners included voting (84%), and providing policy information to consumers or other professionals (77%). Perceived barriers to influencing policy were time, (64%), and other priorities (46%). Perceived benefits to influencing policy included improving the health of the public (94%) and making a difference in others' lives (87%). Only 15% perceived their knowledge regarding the process of changing public policy was excellent. Although health commissioners are often spokespersons for health agencies and communities, their public policy involvement is marginal. Professional preparation programs and continuing education opportunities should focus on advocacy, public policy development, and removing barriers to action.