Alkaptonuria is a rare disorder that results from an inherited deficiency of aromatic amino acid metabolism. Only 21% of the children under the age of 1 year having the disease are identified in clinics. We report a case of a 1-week-old child of a first-degree consanguineous couple with a symptom of frequent nappy staining. Analysis of urine showed a homogentisic acid concentration exceeding 200 mg/dL. The physical examination revealed that the child was healthy. The parents’ watchfulness and the close attention paid to the child were the keys to the early detection of this rare disease. After identifying the disease, adequate follow-up of the patient is important to reduce further complications. Anti-inflammatory therapy and increasing the muscle strength by exercises such as swimming would be useful to restrict joint pains and immobilisation. A low protein diet also could be recommended; that fact is yet to be proven by clinical trials.