Non-ketotic hyperglycinemia (NKGH) is an autosomal recessive disorder of glycine metabolism. Defective glycine cleavage results in elevated concentrations of glycine in plasma, urine and cerebrospinal fluid. The accumulation of glycine, an inhibitory neurotransmitter, leads to a clinical presentation of apnea, lethargy, hypotonia, seizures, and severe psychomotor retardation. There are four clinical variants of NKHG, which have been described in the medical literature. Neonatal NKHG is the most common as well as the most devastating and lethal form of the disorder. Given the multi-system involvement of the disorder, there are several perioperative concerns of such patients with delayed emergence requiring supported ventilation being a common postoperative outcome for NKHG patients. We report the perioperative management of a 4-year-old boy with NKGH who required anesthetic care during an adenoidectomy and tonsillectomy for obstructive sleep apnea.