This pilot study aimed to test a behavioural intervention by outpatient physiotherapists to promote moderate physical activity among their clients for general health reasons. A quasi-experimental study was conducted with 204 subjects. The intervention consisted of behavioural counselling, information brochures and a physical activity diary. Self-reported physical activity was measured at baseline and at six weeks follow-up. At follow-up, the improvements in total minutes of physical activity using the preceding week as the recall period were substantial in both the control and intervention groups, but not significantly different. In the average weekly physical activity reported by subjects for the preceding six months, intervention subjects were significantly more likely to report a 60min/wk improvement than controls (adjusted odds ratio 2.97, 95% confidence interval [CI] 1.36-6.46). However, this was the only significant difference evident between the groups in the average weekly physical activity measures. Pre- and post-surveys completed by participating physiotherapists showed marked improvements in their knowledge and confidence regarding physical activity promotion. While the capacity of outpatient physiotherapists to educate clients about physical activity for non-therapeutic reasons can be improved, the most effective intervention model for clients in this setting remains unclear.