Maple syrup urine disease (MSUD) is a rare genetic metabolic disorder primarily affecting infants and children. It results from the body's inability to break down three essential amino acids: leucine, isoleucine, and valine. This failure leads to a toxic buildup of these amino acids and their byproducts, causing urine, sweat, and earwax to emit a distinctive sweet smell reminiscent of maple syrup. MSUD can manifest in several forms: classic, intermediate, intermittent, and thiamine-responsive, with symptoms ranging from irritability to severe metabolic crises. If left untreated, MSUD can lead to serious complications such as brain damage, developmental delays, and even death. While the disorder is rare, with an incidence of about 1 in 185,000 births, certain populations experience higher rates. Diagnosis can be made through prenatal testing or blood tests after birth. Management includes a strict diet low in protein, regular monitoring, and for some, high doses of vitamin B1. Liver transplants offer a potential cure by supplying the enzymes necessary for amino acid metabolism, allowing patients to live symptom-free.