The objective and aim of the study was to compile empirical data to quantify the underestimation of the true burden of drowning and to compare drowning rates using commonly reported codes compared with those revealed by use of the full range of drowning codes in ICD version 10. The authors reviewed mortality data (1999-2002) from Australia and the USA and compiled data to compare the burden of 'unintentional drowning' with that of 'all drowning'. In both Australia and the USA, drowning mortality is more than 35% higher when a full range of codes is examined. A more comprehensive representation of the drowning problem is needed to assist in strengthening prevention activities.