Trigger finger, or digital stenosing tenosynovitis, is a common hand problem. A widely accepted treatment is steroid injection into the flexor tendon sheath. This can cause rupture of the flexor tendon. However, to the best of our knowledge, there is no report on tendon rupture after a single corticosteroid injection. Moreover, there are no guidelines for patients with tendinopathy who want to return to sports after corticosteroid injection. Clinicians who perform local steroid injections for tendinopathy treatment should be aware of the possible dangers of tendon rupture and should confirm that steroids are not administrated into the tendon. Patients should also be warned about returning to sports prematurely and should be encouraged to gradually resume sports after the injection to prevent further damage. Herein, we report an unusual case of flexor digitorum profundus rupture after a single corticosteroid injection in a 57-yr-old male golfer and we also present a review of the literature.