Purpose: This study was performed to investigate contraception knowledge and sexual behavior in female high school students. Methods: The participants were 382 female high school students from one academic and one vocational school. Data was collected from October to November, 2008 using self report questionnaire. Results: Knowledge on contraception was 5.52 in maximum 14 point scale. Major information source for sexual matters was peers such as friends or sisters. Perception on sexual behavior was different according to major information source. Fifty five percents of students thought that kiss can be permitted, and regarded sexual behavior as natural development. 3.4% of participants had experience of sexual intercourse. Conclusion: It is indicated that perception on sexual behavior can be shaped according to correct information and positive attitude on natural sexual development by health profession. Also, education on contraception would be included in sex education to reduce teenage pregnancy.