Adolescence is a stage in life that is considered very turbulent as the psychological, social and physiological changes that accompany this period predispose young people to risky sexual behavior. The objective of this study was to assess psychosocial predictors of attitude toward premarital sex among Injibara university first year students. Correlational design was used and the target population of this study consists of 1698 adolescent students 280 students were selected as sample using simple random sampling method and also availability sampling technique was used. Hence, 280 adolescent students (147 males and 133 females) participated in this study. Relevant data were collected using questionnaire. The data were quantitatively analyzed using (inferential statistics) logistic regression, one sample t test and independent sample t test. This study indicate that level of and exposure to peer pressure among first year university student having the experience of premarital sex have below average level of self-esteem (t= -46.93, p=.000) and have been exposed to higher level of peer pressure (t= 26.11, p=.000). Study suggests that male first year students with the experience of premarital sex have higher level of self-esteem and exposure to peer pressure than their female counterparts. Self-esteem negatively predicted attitude towards premarital sex. Therefore researcher recommended opening effective counseling office and gender based guidance to first year students and finally researcher recommend the university administrators to see seriously how adolescent student are get life skill training before starting teaching learning process