Introduction. Active patients may benefit from surgical repair of the achilles tendon with the aim of preserving functional length and optimising push-off power. A mini-open device assisted technique has the potential to reduce wound complications, but risks nerve injury. We present the largest published series of midsubstance achilles tendon repairs using the Achillon® device. Methods. A prospective cohort study was run at the Princess Royal Devon & Exeter Hospital between 2008 and 2015. We included all patients who presented with a midsubstance Achilles tendon rupture within 2 weeks of injury, and device assisted mini-open repair was offered to a young active adult population. All patients in the conservative and surgical treatment pathway had the same functional rehabilitation protocol with a plaster for 2 weeks, and a VACOped boot in reducing equinus for a further 8 weeks. Results. 354 patients presented with a midsubstance achilles tendon rupture over a 7-year period, of which 204 had conservative treatment and 150 patients had surgical repair with the Achillon device. Patients were assessed clinically for a minimum of 10 weeks, with long-term notes surveillance for late complications. The rerupture rate for conservative treatment was 1.5%, with no reruptures in the Achillon group. Infections in the surgical group were superficial in 2 cases (1.3%) and deep in 3 cases (2%). Pulmonary embolus occurred in 2 Achillon cases (1.3%), and 1 conservatively managed case (0.5%). There was 1 case of temporary sural nerve irritation in each group. Discussion. Our series show encouraging results for the Achillon® repair with no reruptures and a low complication profile. Functional rehabilitation is likely to have contributed to the low rerupture rate. Studies are emerging that show earlier and improved calf muscle strength in those having surgical repair, suggesting a role for device assisted mini open repair in a selected population