A research conducted at Surabaya East Java reveal that 40% man and 7% woman of the college students had done premarital intercourse. In this case 10% of them ever got Sexually Transmitted Disease (STD). Meanwhile, there is increasing data of AIDS and positively HIV in East Java year 1985 to 2002 about 48% and 45% irrespectivelly. Based on these data, the study will learn free sex behavior on college students and their attempt to prevent Sexually Transmitted Disease-HIV/AIDS in Surabaya. In otherwise, these were expected to recommend to the Public Health Service to prevent spread of Sexually Transmitted Disease-HIV/AIDS. This study was a descriptive which used a qualitative approach. The observing population take by purposive sampling technique with inclussion criteria such as free sex behavior and students whose college at Surabaya. Some variables, which be analyzed were: demographic characteristic, sexually behavior, knowledge about STD-HIV/AIDS, perception to STD-HIV/AIDS, cues to action, and reinforcing factor from the public health providers. The result showed that effort to prevent spread of Sexually Transmitted Disease€“HIV/AIDS by most free sex college students not maximally yet. It might be caused by their believed that their couple was free from Sexually Transmitted Disease-HIV/AIDS. They enjoy the moment, without thinking on their behavior effect such as Sexually Transmitted Disease€“HIV/AIDS.Key words: prevention, STD, HIV/AIDS, college students