Aim: Alkaptonuria (AKU) is an autosomal recessively inherited disease caused by a deficiency of homogentisate 1,2-dioxygenase. This enzyme converts homogentisic acid (HGA) into maleylacetoacetic acid in the tyrosine degradation pathway. The presence of HGA in urine, ochronosis (bluish-black pigmentation in connective tissues) and arthritis of the spine and the other large joints are the three major features of AKU. Nitisinone and a tyrosine-restricted diet are the treatment options. in this study, we evaluated the demographic and clinical characteristics and also the mutations of our AKU patient.