Basic data about drug abuse, criminality, and a number of other relevant factors were collected in structured interviews with 1,268 persons throughout Sweden as part of a longitudinal study of persons involved in severe drug abuse. All the respondents were admitted to institutional care in one of 31 treatment units in 1982 and 1983. Interviews were conducted while the subjects were in treatment. Criminal records were examined in the Swedish Police Register up to December 1990. Findings show that the extent of criminality was much less among females than among males, and fewer women than men had committed criminal offenses. The pattern of criminality varied between the sexes. The first offenses of women occurred later in their lives than was the case with men, and the women committed less violent crimes and more drug-related crimes. The majority of women supported themselves in ways other than through money gained from criminal offenses. Also, women tended to have a more severe pattern of abuse, a more rapid drug career, and more complex psychological problems than men. A subgroup of prostitutes whose drug of choice was heroin often began drug use early with cannabis and went on to amphetamines for their first injection, which often occurred in a junkie pad. There was also a criminal group (as there was among men) with a very early and intensive juvenile delinquency pattern, early drug use, and a rapid transition to regular drug abuse and extensive adult criminality. Forty-two percent of the women had no criminal records; they had more extensive multiple drug abuse than the other women; this was also true for the noncriminal male addicts. The study shows that drug abuse and criminality are interrelated for certain individuals, but not for others. 5 tables and 40 references