Purpose: This study described the use of dog parks in several diverse locations and explored the contribution dog parks made to physical activity of the dog owners. Method: The Systematic Observation of Play and Recreation in Communities (SOPARC) tool was used to count the number and characteristics of people using parks. Observations were conducted 4 times per day, 4 days per week during for 1 week in 6 urban/suburban parks during different seasons. Collection sites included 3 dog parks in Chapel Hill/Durham, NC; 2 dog parks in Los Angeles, CA; and 1 dog park in Philadelphia, PA. Interviews at the NC and PA parks were conducted among 604 adults. Results: We counted 2,124 people (11.9%) in the dog park area compared with 15,672 people in the remaining park areas. Based on observations, dog park visitors were more likely to be female and White or Other race/ethnicity compared with Hispanics, and were less likely to be children or engaged in walking or vigorous activity. Park interviews revealed that compared with other park activities, reporting walking/watching a dog at the park was more common among those who visited the park more frequently (= 1 time per week), stayed at the park for a shorter time (= 1 hr), or visited the park alone. Conclusion: Although dog parks may be an important destination for dog owners and contribute to physical activity, the contribution of dog parks to participants' moderate-to-vigorous physical activity was limited.