The results cast doubt on the stereotypical depiction of female heroin users as prostitutes. While more than 70 percent of the respondents reported involvement in at least one act of prostitution over the previous 12 months, only 37 percent of the 55,790 offenses reported during that period were acts of prostitution. The data indicate that, while female heroin users may engage in prostitution, they also participate in many other criminal activities, and prostitution may not constitute as significant a source of support as has been commonly assumed. There were also differences in criminal involvement between heroin users who were and who were not prostitutes; criminal activity seemed to correspond to degree of involvement in prostitution. 6 tables and 16 notes