Arterial stiffness is predictive of cardiovascular events and is elevated in chronic obstructive pulmonary disease (COPD). As physical inactivity and exercise intolerance are associated with elevated arterial stiffness in health, we hypothesized that lower physical activity would be related to increased arterial stiffness in COPD; and that active COPD patients would have reduced arterial stiffness compared to sedentary counterparts. Arterial stiffness was evaluated using pulse wave velocity (PWV) in 33 COPD patients (FEV₁=65% predicted) and 10 controls. FEV(₁%pred), peak oxygen consumption (VO(₂peak)), and physical activity data were obtained. The inactive COPD group had higher PWV than controls (9.6 vs. 8.3 ms(-1), p<0.05); while there was no difference in PWV between the active COPD group and controls. Within the COPD patients, VO(₂peak) (r=-0.44, p=0.01) and physical activity (r=-0.38, p=0.03) were the best predictors of PWV. Physical inactivity and exercise intolerance appear to be related to arterial stiffness in COPD, and may contribute to increased cardiovascular disease risk in COPD.