A cross sectional study was done to evaluate knowledge, attitude and practice regarding premarital sexual activity among 1408 secondary school students age between 16 to 19 years in Kota Bharu, Kelantan. Statistical analysis showed sexuality knowledge score was significantly associated with sex and age, but not associated with race of the students. Female and older students were more conservative in heterosexual relations attitude. The overall attitude score was relatively high rejection of sexual myths. Female students have liberal view of abortion as an acceptable method of birth control. Male students were more experienced than females on sexual practice. The prevalence of premarital sexual activity among the secondary school students was 7.3% (103), male 14.1% (84) and female 2.3% (19). Among the student who were sexually active about 55 (41%) did not use any protection, 55 (41%) used condom, while 11 (8.2%) used oral contraceptive pill or traditional method. Majority of the students 58.1% (818) had never discussed about sexual matters with their parents. The students have relatively high sexuality knowledge but conservative in their sexual attitude.