This study examined differences in weekly time spent in physical activity by level of perceived environmental resources, 6 months following graduation from cardiac rehabilitation. A descriptive, longitudinal design used standardized measures to evaluate perceived environmental resources and physical activity levels. Repeated measures analysis of variance was used to examine mean differences in weekly time spent in physical activity by level of perceived environmental resources. Adults 51 to 86 years old (N = 150) diagnosed with coronary heart disease were included. There was a significant change over time in physical activity as measured by minutes per week, F(2, 148) = 7.915, p = .001, where activity increased between baseline and 3 months, and then dropped slightly at 6 months. This change over time differed by the level of perceived neighborhood resources, F(2, 148) = 3.545, p = .032. Home and neighborhood resources may positively influence physical activity maintenance following cardiac rehabilitation.