This study investigated whether the opportunity to obtain Continuing Medical Education (CME) credit together with a five-dollar bill increased response rates and questionnaire completion rates in a physician survey involving mailed questionnaires. One thousand, three hundred and fourteen cardiologists, family practitioners, general internists (non-surgeons) and 264 vascular surgeons randomly identified from the American Medical Association database participated. After two, of up to four, questionnaire mailings, the opportunity to obtain CME credit and a five-dollar bill were included with questionnaire mailings. Among non-surgeons, 26.5% responded to pre-incentive mailings and 30.2% of those initially unresponsive replied after the interventions. Among surgeons, 39% responded to pre-incentive mailings and 32.7% of those initially unresponsive replied after the interventions. In conclusion, the opportunity to receive CME credit combined with a small monetary incentive is an effective motivation for physicians participating in a study involving mailed questionnaires.