Abstract Background Supervised exercise programmes for intermittent claudication have poor access and limited compliance. Neuromuscular electrical stimulation (NMES) may be an effective alternative. A proof-of-concept study and RCT were conducted. Methods In study 1, eligible patients underwent baseline assessment; treadmill testing for initial (ICD) and maximum (MCD) claudication distance; EuroQoL Five Dimensions five-level instrument (EQ-5D-5L™) and Intermittent Claudication Questionnaire (ICQ) assessment; and measurement of ultrasound haemodynamics of the superficial femoral artery. After familiarization with the NMES device, participants underwent a 30-min session of stimulation with concomitant recording of haemodynamic measures at 15 min, and after device cessation. Measurements were repeated after 6 weeks of daily use of NMES. In study 2, consecutive patients underwent baseline assessment before online randomization to a supervised exercise programme only, or adjunctive NMES treatment for 6 weeks, followed by repeat measurements. Results Study 1 (20 patients) showed a significant improvement in MCD (46 per cent; P < 0·001) and ICD (71 per cent; P < 0·001). The RCT (42 patients) showed a significant adjunctive benefit of NMES in ICD (46 per cent; P = 0·014). Improvements were seen in the ICQ (9 points; P = 0·009) and EQ-5D-5L™ (P = 0·007) in study 1, and there was a significant adjunctive benefit of NMES on the ICQ score in patients who did supervised exercise (11·2 points; P = 0·031). Blood volume flow and time-adjusted mean velocity increased significantly with the device on (P < 0·050). Overall, NMES compliance exceeded 95 per cent. Conclusion Footplate NMES significantly improved walking distance in patients with intermittent claudication when used independently and also as an adjunct to supervised exercise. Registration number: trial 1, NCT02436200; trial 2, NCT02429310 (http://www.clinicaltrials.gov).