Objective: To explore sexual behavior in terms of masturbation, homosexual contact and coitus in secondary school students in Bangkok.
Material and Method: This was a cross-sectional survey research from December, 2002 to January, 2003. 362 students were selected by the multistages simple random sampling technique. A self administered questionnaire was used to collect data on baseline characteristics and sexual behavior of the students.
Results: 197 male and 165 female students were enrolled in the present study. The mean age was 16.5 years, and 65.7 percent of the students were exposed to sexually explicit contents via the internet. 58.0 percent of the students used the internet for pornographic viewing. According to the sexual behavior of the students, 79.2 percent of the males and 9.1 percent of the females had experience in masturbation (p < 0.05). The male
had a slightly higher in homosexual contact than the females (10.2% vs 9.1%) but coital experience of the males was markedly significance higher than the females (25.4% vs 7.9%) (P < 0.05).
Conclusion: It was concluded that sexual behavior in the internet era; males had more experience in all these categories than females. Sexual education via the internet should be improved in order to make adolescents understand appropriate sexual behavior and practice safer sex.

Keywords: Sexual behavior, Adolescence, Internet