The National Police Custody Survey was conducted as part of a comprehensive criminal justice research program in which the full cooperation of Australia's eight police forces was essential. The 15-item questionnaire was structured to make its completion as quick and simple as possible for police officers and to maximize the likelihood of its being completed accurately. Survey results revealed that 28,566 police custody incidents occurred during August 1988 that involved 23,877 separate individuals. Aboriginal people made up almost 29 percent of the total, having a custody rate 27 times that of non-Aboriginal people. Public drunkenness was the most frequent reason for custody, accounting for 35 percent of cases. The median length of time in police cells was 5.9 hours. Extrapolating the 28,566 police custody incidents in August for the entire 1988 year resulted in an estimated 336,000 occasions of police custody. 15 references and 5 tables (Author abstract modified)