2-Hydroxyisovaleric acid (also known as 2-Hydroxy-3-methylbutyric acid) is a metabolite found in the urine patients with acidosis and diabetic ketoacidosis. The concentration of this metabolite was also abnormal high in the urine of severely asphyxiated group. In case of maple syrup urine disease, when also the concentration of the 2-hydroxyisovaleric acid was increased in the urine, was made a suggestion, that the early diagnosis and proper treatment can prevent brain damage and improve prognosis.