The volume of the mouth and pharynx was measured in 20 cadavers and ranged from 25 to 202 ml with a median value of 87 ml, a mean of 90.7 ml and a geometric (logarithmic) mean of 78.3 ml. The volume that encompasses 99% of the normal population is estimated as 215 ml if the assumption of a normal Gaussian distribution is made, or 342 ml [corrected] if a log-normal distribution is assumed. Collection containers in suction equipment intended for removing vomit from the pharynx and mouth in adults should have a useable volume of at least 500 ml.