An anesthetic vaporizer filler valve is disclosed that can be used in conjunction with anesthetic agent bottles currently commercially available and which have standard keying systems with rotating collars having lugs extending therefrom. The standard collar of such anesthetic agent bottles is keyed into the vaporizer filling valve. the vaporizer filler valve has an internal valve that must be opened in order to introduce the liquid anesthetic agent into the vaporizer sump. By means of a corresponding slot in the vaporizer filler valve that correspond with mating lugs of the standard anesthetic agent bottle, only a proper anesthetic agent bottle can engage and be screwed into the filler valve designed for that specific anesthetic agent.