Research on the relationships between drugs and crime in women has been inhibited by the small proportion of females involved in drug offenses, lack of interest, and stereotypes such as the characterization of the female addict as a prostitute. Based on sample populations of addicts in treatment or incarcerated, several studies have documented prostitution as a major means of support for addicted women and discovered differences in criminal behavior between addicts who engage in prostitution and those who do not. In this project, experienced interviewers contacted known female heroin users in the Miami drug community during 1978 and questioned them at length about criminal and arrest histories and criminal involvement with prostitution during the year. The sample of 153 respondents was divided into 3 groups for analysis: users who reported no involvement with prostitution during the 12 months prior to the interview, users who reported between 1 and 125 acts of prostitution during this period, and users who reported 126 or more acts of prostitution. Almost all female users reported having committed at least one crime and about 86 percent indicated that they had been arrested. However, only 15.6 percent of the sample reported prostitution as their first criminal offense, and among those who had been arrested, less than a quarter cited prostitution as the first arrest offense. While over 70 percent reported at least one act of prostitution during the 12-month period, only 37 percent of the reported offenses were acts of prostitution. Excluding prostitution offenses, the most frequently reported crimes by all users were drug sales and shoplifting. Analysis of the data also showed differences in criminal behavior between users/nonprostitutes and users/prostitutes, such as more frequent arrests for user/prostitutes. Female drug users with lower involvement in prostitution reported drug sales as the most frequent offense, whereas those with higher involvement most often reported prostitution. Tables present statistics on first arrests, lifetime arrests, and criminal involvement by offense. Over two-thirds of the sample admitted that some criminal activities had been undertaken to support their drug needs. Further research on female drug users and crime could examine the impact of heroin on criminal patterns, sex roles at various stages of drug use, and how women begin using drugs. The article contains 16 notes.