The study investigated the psychosocial determinants of high and low academic achievers. A small random sample of high and low academic achievers was compared on intelligence to confirm that no significant differences exist in the intellectual ability of high and low academic achievers. Data of the main study was drawn from 187 B.Sc. academic achievers with a distribution of 126 high and 61 low achievers of three successive academic sessions from public university. Independent group research design was used. Purposive sampling technique was used for the collection of data. All the respondents were contacted twice to control the elements which could affect their responses. Statistical analysis was carried out through SPSS Program. Results indicated that high academic achievers have more clarity about their future goals and are less likely to attend tuitions than low academic achievers. However, results showed no significant differences in their family variables. t-test analysis indicated that high academic achievers have significantly effective study orientation, high achievement motivation, low test anxiety, high self-esteem and were high in internal academic locus of control than low academic achievers. Correlation analysis showed a significant positive correlation between academic achievement, study orientation, achievement motivation, and self-esteem. Step-wise regression analysis indicated study orientation followed by the achievement motivation as the best predictor of academic achievement. vi Gender differences for high academic achievers were observed in test anxiety and academic locus of control whereas in case of low academic achievers significant gender differences were found in study orientation, achievement motivation and test anxiety. The study has identified the psychosocial determinants of high and low academic achievers. Results of the study have important implications for policy makers and educationists to improve academic achievement.