lncrease in female adolescents'' premarital sexual activities in conjunction with the multiplicity of sexual partners has also contributed to high incidences of unwanted pregnancies, unsafe abortions, expulsion from home or school and sexually transmitted diseases. Uncontrolled reproductive and sexual behaviour of individuals during period of adolescence could impact negatively on their adult lives. Mismanagement of sexual and reproductive needs predispose them to reproductive health problems. Norms and values of sexual behaviour differ from culture to culture. In most places the determinants of Premarital sexual activity among female secondary school adolescents'' are not known. This book, therefore, analyses the socio-cultural factors (parenting style, value index, mass media, belief system, peer pressure, parental socio-economic status, religion and ethnicity) that could predict the sexual behaviour of female secondary school adolescents in Nigeria. Measures of addressing premarital sexual behaviour of female secondary school adolescents have been addressed by this book.