57 patients surgically treated for neglected Achilles tendon rupture were randomized to receive either early physical rehabilitation or conventional postoperative cast immobilization. The purpose of this study was to compare improvements in clinical outcomes (assessed with the Leppilahti scoring system), calf nerve response, and volume regeneration of the ruptured tendon over a two-year follow-up period. Results demonstrated that patients allocated to early physical rehabilitation had earlier improvement of LSS scores, nerve conduction velocity, electrical latency, and greater cross-sectional area of the ruptured tendon when compared to patients who received cast immobilization only. Additionally, a greater number of cases of small ischemic necrosis of the skin around the tendon, infection, calcified plaques at the healing area, and re-rupture were noted in the immobilization group.