72-year-old patient underwent an elective transurethral resection of the prostate (TURP) performed with a spinal anaesthesia. The irrigation solution contained glycine at a concentration of 15 g.l-1. The patient's level of consciousness deteriorated over the next 4 hours. He went in an areflexic coma with pupillary areflexia and left mydriasis. The diagnosis of TUR syndrome was substantiated by a sodium blood concentration of 98 mmol.l-1, an osmotic gap of 48 mosmol.kg-1 and blood ammonia at 415 mumol.l-1. To investigate the pathophysiological role of glycine and its metabolites, their concentrations were measured by chromatography and spectrometry in plasma and CSF 8, 24 and 48 hours postoperatively. Glycine and its metabolites (serine, alanine, glyoxylic acid and glycolic acid) accumulated during the postoperative period in both blood and CSF. The central nervous system is in direct contact with these neurotropic compounds. Glycine is an inhibitory neurotransmitter, whereas glyoxylic acid and glycolic acid are considered as to be neurotoxic.