Xe is only produced by cryogenic distillation of air, and its availability is limited by the extremely low abundance. Therefore,Xerecovery after usage is the only way to guarantee sufficient supply and broad application. Herein we demonstrate DD3R zeolite as ab enchmark membrane material for CO 2 /Xe separation. The CO 2 permeance after an optimized membrane synthesis is one order magnitude higher than for conventional membranes and is less susceptible to water vapour.T he overall membrane performance is dominated by diffusivity selectivity of CO 2 over Xe in DD3R zeolite membranes,whereby rigidity of the zeolite structure playsakey role. Forr elevant anaesthetic composition (< 5% CO 2 )a nd condition (humid), CO 2 permeance and CO 2 /Xe selectivity stabilized at 2.0 10 À8 mol m À2 s À1 Pa À1 and 67, respectively,d uring long-term operation (> 320 h). This endows DD3R zeolite membranes great potential for on-stream CO 2 removal from the Xe-based closed-circuit anesthesia system. The large cost reduction of up to 4o rders of magnitude by membrane Xerecycling (> 99 + %) allows the use of the precious Xe as anaesthetics gas av iable general option in surgery.