Docetrizoate (trade name: Pulmidol) is the bronchographic agent (radiopaque medium). The most important characteristic of a bronchographic medium, that it should flow readily into small bronchial branches, but not pass into bronchioles, is well fulfilled by Pulmidol. Propyl docetrizoate in 60 or 75 per cent suspension in arachis oil produced satisfactory bronchograms in the cat and in man. The radio-opaque material was cleared from the lung within two to four days, and produced no significant histological changes in the lungs of cats receiving a high concentration into one lobe. Early in 1962 a change to Pulmidol was made because of the increased contrast due to its higher iodine content, but its use had to be discontinued following reports of deaths in children due to its absorption under anaesthesia.