Two horses with acute tendinopathy of a superficial digital flexor tendon ( sdft ) and three horses with chronic proximal desmitis of the suspensory ligament ( pdsl ) were treated by injecting autologous concentrates of their platelets into the lesions. The lesions were monitored ultrasonographically and clinically. There were significant ultrasonographic and clinical improvements in the two horses with sdft , but no ultrasonographic improvements in the horses with pdsl ; however, they improved clinically and became less lame. All the horses had returned to their pre‐injury level of performance by six months after the completion of the treatment, and none of them had suffered a recurrence after 20 months.