['To determine whether persons with poorer lower extremity functioning have reduced physical activity levels.', 'Cross-sectional.', 'Three Chicago-area medical centers.', 'Two hundred twenty-five people with lower extremity peripheral arterial disease (PAD) and 121 individuals without PAD.', 'The summary performance score (SPS) was determined for all participants. The SPS combines data on walking velocity, time for five repeated chair rises, and standing balance. Each test is scored on a 0 to 4 scale (4 = best). Scores are summed to create the SPS (0-12 scale, 12 = best). All participants wore a vertical accelerometer for 7 days to measure physical activity.', 'The SPS was associated linearly with 7-day physical activity levels of participants with (P< .0001) and without PAD (P< .0001). This relationship was maintained even after restricting analyses to subsets of participants who reported that they could walk a quarter of a mile and up and down stairs without difficulty (P< .001) and were able to walk for 6-minutes without stopping (P< .001). In multiple linear regression analyses, the SPS was associated with physical activity in participants with (P< .01) and without PAD (P< .001), adjusting for age, sex, race, comorbidities, ankle brachial index, neuropathy, and leg symptoms.'] Is lower extremity performance associated with daily life physical activity in individuals with and without peripheral arterial disease?