Alkaptonuria is a rare genetic disorder of tyrosine metabolism, due to deficiency of the enzyme homogentisate 1, 2 dioxygenase. This results in characteristic features like blackish urine discoloration, ochronosis, arthropathy, cardiac valve deterioration. In this paper, the authors presenta case report of a 4-month-old boy who was brought by his mother to the well-baby clinic, with a chief complaint of black staining of nappy, a few hours after voiding. A qualitative examination of urine after an hour of the collection showed dark black discoloration, Quantitative examination reveals the presence of homogentisic acid to the extent of200mg/dl. The Diagnosis of Alkaptonuria was confirmed and the infant was started on Vitamin C and put under regular follow-up.