Abstract: A vaporizer that may be used in high-frequency jet ventilation (HFJV) is closed. The vaporizer operates on the principle of airblast atomization. The vaporizer provides inhalation anesthesia and is adaptable to the high pressure requirements of a high frequency jet ventilator. The apparatus consists of a main tube or body which defines a passageway. Vaporization occurs by the principle of airblast atomization inside the passageway. The open end of the main body adapts to a connector of the endotracheal tube. A gas supply needle extends into and is centered within the lumen of the main body and directed along the axis of the body. The gas supply needle may be positioned horizontally and gas is jetted through it from a high-frequency jet ventilator. An inhalation anesthetic supply needle intersects the main body in general proximity to the gas supply needle. Preferably the inhalation anesthetic supply needle intersects the main body in a generally perpendicular manner to the gas supply needle.