As many as 11.9% of teenagers in the world aged 12 to 15 years have had sexual intercourse. National studies in Indonesia revealed that the prevalence of sexual intercourse among unmarried adolescents aged 15 to 24 years is 7.6% for males and 1.5% for females. However, religiously and culturally, sex before marriage is prohibited in Indonesia. Young couples can experience ostracism and social discrimination in society, and even worse if pre- marital sex leads to teenage pregnancy, they may drop out from school. From a total of 180 eligible Early Adults Who Are Prone To Sexual Intercourse (EAWAPTSI) that were recruited by RDS method, we found that almost half of the participants had sexual intercourse before (48.3%) and two third of them are male (32.2%). Almost all of the EA that ever experienced sexual intercourse had never (26.1%) or rarely (16.7%) discussion about sexuality with their parents. We can conclude that there are several EA who have already been involved in sexual intercourse. Therefore, comprehensive education on healthy sexual behavior should be started early.