The objective of this study was to know the magnitude of potential spreading of HIV from the Intravenous Drug Users (IDUs) to the general population. This study analyzed secondary data from the Behavioral Surveillance Survey in Jakarta year 2000 conducted by the Center for Health Research,University of Indonesia. The method of computation was based on the concept of probability. The HIV could spread to the general population if the IDUs have had sexual act without using condoms. The result of the study showed that potential spreading of HIV from the IDUs to the general population was very high. A total of 27,300 IDUs in DKI Jakarta (year 2000) will produce 1.062—3.368 HIV new cases per year, or equivalent with 389 – 1.245 HIV new cases per year per 10.000 IDUs. To minimize the potential spreading, it is suggested to conduct some strategies e.g. using sterile syringes, detoxification, education information and communication about harmful effects of drugs and AIDS, reducing and localizing the distribution of drugs, campaign of condom use, increasing of community participation to prevent illegal drug use and well coming without any discrimination ex-IDUs who has been recovered.