Lesch-Nyhan syndrome (LNS) is a rare X-linked recessive disorder, is characterized by mental retardation, spasticity, extrapyramidal signs, hyperuricaemia and self-destructive behavior resulting in self-mutilation through biting and scratching. It is also known as Nyhan’s syndrome, Kelley-Seegmiller syndrome and Juvenile gout, caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT), produced by mutations in the HPRT gene. We report a six year old boy with developmental retardation, involuntary movements, and self-injurious behavior.