Of the 74 deaths in 1993, 48 (65 percent) occurred in prison custody, while 25 deaths (34 percent) occurred in police custody. One death was reported to have occurred in the custody of juvenile welfare authorities. All but three of those who died were males. Aboriginal people were overrepresented in the number of custodial deaths, compared to the number of aboriginal people in the general population. Eight aboriginal persons died in custody during 1993, 11 percent of all deaths in custody, but aborigines made up just 1 percent of the Australian population. Ages of those who died ranged from 16 to 73 years; the average age was 34 years. Of the 74 deaths, 31 (42 percent) were reported to have been self-inflicted. The most frequent cause of death for both aboriginal and nonaboriginal people was hanging, followed in frequency by deaths from illness and injury. Five serious offenses (homicide, assault, sex offenses, robbery, and other offenses against the person) accounted for 36 deaths in custody (49 percent); 32 persons who died were serving a sentence of imprisonment at the time of death, and 22 were being held on remand. The 20 remaining cases had not been convicted of any offense but died while police were attempting to detain them, while being escorted by police to a psychiatric facility, while in protective custody for drunkenness, or while being detained but considered unfit to plead to the offense committed. The number of custodial deaths in 1993 was substantially higher than the total number reported in the previous 5 years, and this increase occurred entirely among nonaboriginal people. No aborigines died in police lockups during 1993, although two died in other forms of police custody and six died in prison. Trends in custody deaths between 1980 and 1993 are reviewed, and death rates are compared for various population groups. 8 references, 11 tables, and 5 figures