BACKGROUND The aim was to investigate the effect of ramipril on clinical parameters in patients with peripheral arterial disease. METHODS Patients with intermittent claudication were randomized to receive ramipril or placebo for 24 weeks in a double-blind study. Outcome measures were walking distance, arterial stiffness measurement and quality of life (QoL). RESULTS A total of 33 patients were included (25 men; mean(s.d.) age 64.6(7.8) years); 14 received ramipril and 19 placebo. After 24 weeks, ramipril improved maximum treadmill walking distance by an adjusted mean (95 per cent confidence interval, c.i.) of 131 (62 to 199) m (P = 0·001), improved treadmill intermittent claudication distance by 122 (56 to 188) m (P = 0.001) and improved patient-reported walking distance by 159 (66 to 313) m (P = 0.043) compared with placebo. Ramipril reduced carotid femoral pulse wave velocity by -1.47 (95 per cent c.i. -2.40 to -0.57) m/s compared with placebo (P = 0.002). Resting ankle : brachial pressure index (ABPI) improved slightly in both ramipril and placebo groups (0.02 (95 per cent c.i. -0.08 to 0.11) versus 0.03 (-0.05 to 0.10); P = 0.830). Ramipril had a slight, non-significant effect on QoL physical domains compared with placebo. CONCLUSIONS Ramipril improved walking distance in patients with claudication; however, this improvement was not related to improved ABPI but might have been due to ramipril reducing arterial stiffness. BACKGROUND NCT01037530 (http://www.clinicaltrials.gov).