Academic self–efficacy can be defined as person`s belief that he can successfully achieve at a desired level on an academic task or a specific goal (Schunk & Pajares, 2002). This study aims to investigate the level of academic self-efficacy levels of pre-service and in-service teachers. In this study problem solving skills and epistemological beliefs are evaluated as predictors of academic self-efficacy levels of pre-service and in-service groups. Each groups are consisting of 40 people. The data gathered via online questionnaire form via link given in the Facebook group pages. The gathered data analyzed using regression, t-test and related descriptive analysis. The results show that epistemological beliefs and problem solving skills can predict the %14 for in-service English language teachers and this is %15 for pre-service English language teachers. Besides the results show that when the relationship between the gender and the other dependent factors there is only relation in pre-service teachers ‘academic self-efficacy and epistemological beliefs. The female participants have higher values than male ones.