Surgical repair of the Achilles tendon can lead to prolonged calf atrophy and functional limitations, even with early weightbearing. The use of neuromuscular electrical stimulation (NMES) has been studied in muscle rehabilitation programs following anterior cruciate ligament repair. Accelerated recovery and pain reduction were noted. The aim of the present study was to evaluate the use of electrical stimulation on maintaining calf muscle cross-sectional area volume and improving patient reported outcome measures following Achilles tendon surgery. Randomized controlled clinical trial. Forty patients were enrolled. All patients had undergone repair of the Achilles tendon. A 4 lead NMES device was applied at time of surgery with both patient and surgeon blinded to activity of the device. All patients followed a standardized postoperative protocol. Group 1 consisted of 20 patients who received protocol specific NMES. Group 2 was the "sham device" control group, receiving subtherapeutic electrical stimulation. Preoperative and postoperative calf circumference (2, 6, 12 weeks) and magnetic resonance imaging (MRI) scans (2, 6 weeks) were conducted. Patient-reported functional outcome scores were measured. Of the 40 patients, 23 (57.5%) were male and 17 (42.5%) were female. The mean age was 48.9 years (11.1 standard deviation [SD]) with a mean body mass index of 32.2 kg/m (5.7 SD). Calf measurements for Group 1 (39.3 cm and 39.7 cm) were slightly higher compared Group 2 (38.4 cm and 39.2 cm) at 6 and 12 weeks postoperative. Functional scores were similar between Groups 1 and 2 at final follow-up. Foot/Ankle Computer Adaptive Test scores were 55.1 (6.9 SD) versus 58.4(8.6 SD), and American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scores were 82.3 (8.2 SD) and 83.9 (9.3 SD), respectively. The visual analog scale at 12-week visit for Groups 1 and 2 was 8.4 (9.3 SD) and 8.4 (9.1 SD), respectively. This prospective randomized controlled trial was undertaken to quantify and validate the effect and ability of NMES to minimize calf atrophy after acute or chronic repair. No statistically significant difference was found between active NMES and sham control group. There was a trend showing some maintenance of calf volume per MRI study.