The study examined secondary school adolescent’s sexual behavior in Gboko, Benue State Nigeria. A total of 488 Nigeria adolescents took part in the study. A cross-sectional survey design was used. The safe sex behavior scale was used for data collection. Three hypotheses were tested at alpha level of 0.05 using independent t-test. The first hypothesis established a significant difference between junior and senior secondary school adolescents on sexual behavior (t(df=486) = 2.88; p<.05), and there was a significant difference between male and female secondary school adolescents on sexual behavior (t(df=478) = 1.65; p<.05). Also significant difference was found between Nigerian day and boarding students on sexual behavior (t(df=486) = 1.56; p<.05) Based on the findings, level of class of secondary school, Gender and type of school in Nigeria play important role in Adolescent sexual behavior and therefore it was recommended that proper guidance counseling and sex education should be given to adolescents on sexual behavior.