Alkaptonuria is an autosomal recessive disease caused by the accumulation of homogentisic acid (HGA) products in the ligament, cartilage, skin and various organs due to the lack of HGA oxidase enzyme. In this article, we present a 61-year-old male patient operated on due to a diagnosis of spontaneous Achilles tendon rupture and diagnosed as alkaptonuria due to the intraoperative color of the tissues and the subsequent examinations. We also reviewed alkaptonuria and its accompanying pathologies in light of the literature.