Issues addressed: The presence of a household dog may be of benefit to the health of owners. One reason may be because of increased physical activity through regular dog walking. We sought to build on existing dog walking research with more detailed examination of the characteristics of both dogs and owners in relation to the owners' physical activity. Methods: A population-based sample (n=1,237) of residents in central Queensland, Australia, were interviewed by computer-aided telephone interview to collect dog-related and physical activity data. Results: Results showed that the simple presence of a household dog displayed no relationship to the acquisition of sufficient levels of physical activity in the overall population. This finding was mediated, in terms of recreational walking, by dog size, with respondents in households with medium or large dogs displaying significantly more minutes of recreational walking per week than those with small dogs, or no dog at all. In addition, respondents who were involved in walking their household's dog were more likely to meet established physical activity guidelines than those who did not. Conclusions: Dog ownership appears to offer the promise of affecting physical activity, but more work needs to be done to determine the contribution of ownership, dog type, and dog-walking frequency with regard to achieving health-related, physical activity guidelines.