Achilles tendonitis is a significant disability in the runner and may often cause runners to lose an entire season of competition. The exact pathophysiology of the problem is uncertain. However, it is the belief of the authors that Achilles tendonitis in the runner often represents a microscopic tear in the tendon which, if not adequately treated, may lead to a macroscopic tear. We recommend surgical treatment in those patients with chronic symptoms who have not responded to conservative measures.