Health and exercise professionals have an important role to play in the promotion of physical activity (PA), in that they can provide PA advice to their patients and clients. In order for them to do this, they must be aware of, and understand, current PA guidelines and messages. This study aimed to compare levels of awareness and understanding of the moderate PA message among delegates at the 1999 Australian Conference of Science and Medicine in Sport (ACSMS) with those of delegates at the 2007 ACSMS. The same self-report survey that was used in 1999 was administered to delegates attending the 2007 ACSMS during a plenary session. In 1999, 34% of respondents (N = 292) had heard of the US Surgeon General's (USSG) report and the corresponding PA guidelines. In 2007 this awareness was 70% (N = 241). Despite this increase, there was a decline in understanding of the moderate PA message: In 2007, 19% of respondents correctly answered four out of five questions about the PA guidelines, compared with 43% in 1999 (p < 0.000). There was however an increase in the proportion who acknowledged that "discussing the benefits of moderate PA is part of my professional role" (from 53.1% in 1999 to 86.5% in 2007). While awareness of the PA guidelines and acknowledgment of the role of health and exercise professionals in promoting PA have increased, many delegates did not understand the moderate physical activity message. As was the case in 1999, there is still a need for professional education strategies to be developed in this area.