Objective: To evaluate three strategies for promoting physical activity (PA) in a primary care setting. Method: Data were collected between 2002 and 2004 from 136 patients attending two general practices in Brisbane, Australia. Inactive patients (50-70 years) were randomly allocated to one of three hierarchical intervention groups: the general practitioner (GP) group received 'brief' advice; the GP+ES group also received behavior change advice from an exercise scientist (ES); and the GP+ES+P group also received a pedometer. Self-reported PA and its determinants were measured at baseline and weeks 12 and 24. Cardio-respiratory variables were measured at baseline and week 12. Results: Overall, mean PA time increased by 84 and 128 min/week at weeks 12 and 24 (p < .01) with no significant group differences. Small improvements in blood pressure and post-exercise heart rate were observed. At week 24, the GP+ES+P group were more likely to report meeting PA guidelines than the GP group (OR = 2.39 95% CI: 1.01, 5.64). Conclusion: PA levels can be increased in mid- to older-age adults, either by brief advice from motivated GPs alone, or from collaboration between GPs and ESs. The most intense intervention (GP+ES+P) showed the most promising results.