Hysteroscopic surgery with the use of a resectoscope are currently going through major developments. They are often aimed at healthy women who consider having relatively minor surgery. Many complications can affect endometrial resection. Some metabolic complications due to the irrigating liquid have been identified recently in gynaecological surgery, and can be defined as the whole group of clinical symptoms linked to the passage of the irrigation liquid into systemic circulation. Neurological and cardiovascular disorders are due to an acute dilutional hyponatremia and to the very toxicity of glycol and/or of its metabolites. The way the irrigating liquid is resorbed has an effect on the order in which these accidents happen. The duration of the resection, its depth, as well as the intrauterine pressure are the three factors which make it easier for a clinical syndrome to appear. Whatever the mechanism responsible, the clinical and biological consequences are the same and can be more or less serious, depending on how much liquid has been resorbed: they are non-existent up to one liter, and appear between 1.5 and 2 liters. Recent studies have shown that natremia and glycinemia are closely and inversely related. By taking a number of precautions, accidents--which are relatively rare but can be very serious--could be prevented.