Background: Premarital sexual practice among unmarried preparatory, College & university level students have markedly increased recently in Ethiopia. Those students found in adolescent are recognized as most affected by sexually transmitted infections including HIV/AIDS. Sexual activity among unmarried people who do not have access to information about reproductive health and birth control can also increase the rate of unwanted early pregnancy too. A cross sectional study among TVET students was conducted from April-May 2016.Three hundred eighty seven adolescent students were participated. A self-administered questionnaire was provided. The data were cleaned, entered, processed and analyzed using SPSS V.21. The results was summarized in frequencies and percentages and presented in tables, pie chart and graph. The prevalence of premarital sexual practice among the TVET students was 51.9%. Being Male, family monthly income, alcohol consumption, cigarette smoking and chewing chat were factors associated with premarital sexual practice. Premarital sexual practice was more likely to occur among male adolescent students, [AOR 0.274, 95% (0.143, 0.525)]. Hence, this study showed that the prevalence of premarital sex practice among the study participants is higher (52%). Awareness creation should be done among TVET students to avoid unhealthy behaviors like substance use (drinking alcohol), watching videos that push them to start pre-marital sexual practice.