Given the magnitude of the diabetes epidemic among Canadian Aboriginals and the corresponding need to develop physical activity interventions, the aims of this study were to: 1) examine the meaning of physical activity; 2) assess physical activity behavior levels; and 3) examine the association of key Social Cognitive Theory (SCT) constructs with physical activity behavior. Thirty-four Aboriginals with diabetes completed a survey composed of questions regarding: 1) the perceived meaning of physical activity; 2) physical activity behavior; and 3) SCT constructs. An emerging theme revealed that some participants perceived physical activity leisure-time activities as appropriate across the lifespan, while the majority perceived leisure-time activities to be only for youth. Based on the reported energy expenditure estimates, 61.5% of participants were categorized as sedentary. However, when occupational and household activities were taken into account, 33.0% were categorized as sedentary. Bivariate correlations revealed that no SCT constructs were significantly associated with energy expenditure scores. Results suggest that specific SCT construct items may help understand physical activity behavior change.