To investigate adolescents' one-night stands experiences in terms of meaning, process, influencing factors, and effects. In-depth interviews are used for data collection from 20 samples, 10 males and 10 females, aged 20-25 residing in Bangkok Metropolis. The meaning of one-night stands is the sexual relationship between males and females who do not know or are not familiar with each other before their agreement to have sexual intercourse without love and responsibility, but just for fulfilling sexual desire; the relationships start and end rapidly. Visiting entertaining establishments at night with friends is the most frequently reported process that leads to their one-night stands experiences by the samples. The less are contacting by phone with persons whom friends introduce, and joining parties at friends' house or going upcountry with friends. Factors influencing one-night stands of the samples cover internal factors including their attitude towards sex, past experiences with love and sex, their meaning of one-night stands, and their expectations to have one-night stands. External factors also lead to these sexual behaviors, such as alcohol consumption, atmosphere, and friends. Alcohol consumption is the most important factor. The effects of one-night stands that are often found are psychological condition including anxiety of infections with sexual transmitted diseases and AIDS, getting pregnancy and feeling guilty. Exhausting only is the physical condition mentioned by one sample