The efficacy of an autologous platelet concentrate (APC) in 5 horses with soft tissue musculoskeletal injuries namely: superficial digital flexor tendon (SDFT) tendinopathy and suspensory ligament desmopathy (DSL), was evaluated.Initial degree of lameness, flexion test response, ultrasonographic images and long term (1 year) clinical follow-up were documented.Three injections of APC were performed at two week intervals.Horses were evaluated before each injection, two months after the last treatment and one year after.Platelet counts, white blood cell counts and determination of TGF-β 1 levels per ml of APC were performed.Two horses had acute SDFT tendinopathy, 1 had chronic forelimb proximal desmitis (PD) of the suspensory ligament (PDSL), 2 had chronic hindlimb PDSL, and 1 of them also had desmitis of the medial branch of the suspensory ligament of the right hindlimb.All the horses in this study presented a clinical decrease of degree of lameness and response to flexion test, two months after last APC treatment.Ultrasound appearance improved in the horses with SDFT lesions, but remained the same in the horses with DSL.All the horses returned successfully to competition without reinjury.Means of 250 ± 71.8 x 10 6 platelets, 8.68 ± 3.78 leucocytes x 10 6 , and 12.5 ± 2.4 ng of TGF-β 1 per 1 ml of the PC were obtained.