Anaesthesia in low-flow techniques gains increasing interest. The possibility of cost reduction, widespread use of highly developed anaesthesia machines and monitors, and introduction of two new fluorinated inhalational anaesthetics with low solubility in human tissues encourage the use of low-flow anaesthesia techniques. Further advantages are improved climatisation of breathing gas and estimation or even measurement of the important parameter "oxygen consumption". The anaesthesia machines and inhalational anaesthetics currently available allow a safe use of low-flow techniques if safety requirements are complied with (tight circle system, monitoring of: inspired oxygen concentration, minute ventilation, airway pressure, transcutaneous oxygen saturation). Low-flow anaesthesia techniques using a fresh gas flow rate of 1 l/min can be performed with almost every anaesthesia machine. However, the use of multigas monitors, analyzing most parts of the breathing gas, facilitates the use of low-flow techniques. Multigas monitors and anaesthesia machines equipped with intermittent fresh gas delivery are recommended for the use of fresh gas flow rates close to the metabolic rate. Because of its physicochemical properties the new inhalational anaesthetic desflurane offers advantages for the use in low-flow anaesthesia techniques.