24 patients with chronic, mid-portion Achilles tendinopathy were randomized to receive a single injection, under ultrasound guidance, containing either platelet-rich plasma (PRP) or placebo saline. The purpose of this study was to evaluate if an injection with PRP was associated with significantly better Victorian Institute of Sports Assessment-Achilles (VISA-A) scores, the numeric rating scale for pain scores, and ultrasonography measures of color Doppler activity and tendon thickness at 3, 6, and 12-month follow-up. Neither VISA-A scores nor NRS pain scores demonstrated significant differences between groups at 3 months. After the 3-month follow-up, study discontinuation was documented in a number of patients in both groups due to an unsatisfactory outcome.