Objective: To study trends in general practitioners’ knowledge, confidence, and practices in promoting physical activity to patients over a ten year period (1997-2007). Design: Repeated cross sectional population survey. Setting: General practice in New South Wales (Australia). Participants: 646 (40%), 747 (53%), and 511 (64%) general practitioners that were registered in a selection of urban and rural divisions in New South Wales participated in 2007, 2000, and 1997, respectively. Main outcome measures: Self report questionnaire on the general practitioner’s knowledge, confidence, role perception, attendance of continuous professional development, and counselling practice with regard to promoting physical activity in their patients. Results: The majority of general practitioners felt confident in giving physical activity advice and saw it as their role to do so. The proportion of general practitioners with high confidence and role perception increased between 1997 and 2000 (p< 0.001) but remained unchanged thereafter. In 1997, general practitioners were 0.54 times less likely (95%CI 0.42 to 0.69, p< 0.001) to discuss physical activity with more than 10 patients per week than general practitioners in 2007. However, the percentage of new patients that were asked about their physical activity did not change over the last decade. Conclusions: Most increases in the proportion of general practitioners reporting high knowledge, role perception, and confidence in giving physical activity advice to patients occurred between 1997 and 2000, and remained unchanged thereafter. In 2007, general practitioners appeared to give more physical activity advice, but Australian general practice is not yet living up to its potential with regard to physical activity promotion.