Introduction: The presence of commercial messages in continuing medical education (CME) is an ongoing cause of concern. This study identifies actions perceived by CME participants to convey commercial bias from CME faculty. Methods: A questionnaire listing actions associated with CME activities was distributed to 230 randomly selected participants from 7 CME activities designated for AMA PRA Category 1 Credit™. The activities were held over an 8‐month period. Participants were asked to complete the questionnaire before participating in the live activity. Results: Nine actions identified by over 50% of all respondents were perceived to convey commercial bias. The most critical ones reflecting commercial bias were speaking about only one agent, not providing a balanced presentation of all agents, and faculty relationships with commercial supporters. Ten actions identified by over 50% of the respondents were perceived to convey personal opinion of the faculty. The most prevalent actions were the influence of mentors or teachers, relating general practice habits from the faculty member's own experience, and cultural differences among patient populations. More than half the respondents who indicated they perceived commercial bias in certified activities attributed this perception to an overall impression, instead of 1 or 2 specific actions. Discussion: Actions were identified that conveyed differences between commercial messages and personal opinion. CME providers should define commercial bias for participants, faculty, and planners and provide education about that definition.