The relationship between surgical technique and ankle biomechanical properties after surgery for acute rupture of the Achilles tendon (ATR) has not yet been fully investigated. Platelet-rich fibrin (PRF) matrices seem to play a central role in the complex processes of tendon healing. Our aim was to analyze the biomechanical characteristics, stiffness, and mechanical work of the ankle during walking in patients who had undergone surgery after ATR with and without PRF augmentation. We performed a retrospective review of all consecutive patients who had been treated with surgical repair after ATR. Of the 20 male subjects enrolled, 9 (45%) had undergone conventional open repair of the Achilles tendon using the Krackow technique (no-PRF) and 11 (55%) had undergone surgery with PRF augmentation. An additional 8 healthy subjects were included as a control group. A gait analysis evaluation was performed at 6 months after surgery. The percentage of the stance time of the operated leg, double-support time of the healthy leg, and net work of the ankle during the gait cycle showed statistically significant differences between the no-PRF and the healthy group (p < .005). No differences were found between the PRF and healthy groups. Treatment with suture and PRF augmentation could result in significant functional improvements in term of efficiency of motion.