This study investigated the effects of the quality of teaching on students' efficacy beliefs. This study took a descriptive-correlation approach and involved humanities studntes of Ferdowsi university of Mashhad, Iran in during academic year of 2011-2012 as the statistical population. From this population, 366 students were selected through stratified sampling method and based on Morgan and Kerjcie's table. The instrument for this study included a questionnaire which the samples were asked to complete. The data was analyzed by descriptive statistic and regression analysis. The quality of teaching, predicted students' efficacy beliefs (F (364, 1) =30.12, P=0.000) and explained 8% of the self-efficacy variance. The components of assessment (t=3.008, p=0.003) and interpersonal relationships (t=2.197, p=0.029) were positive predictors and lesson plan (t=-3.329, p=0.001) was a negative predictor for students' efficacy beliefs. Nonetheless, the implementation of teaching (t=-0.924, p=0.356) did not predict students' efficacy beliefs. Thus, according to the teachers' lesson plans and teaching performance, self-efficacy beliefs played a small rol. Accordingly, it is recommended that teachers use problem-based teaching methods which improve students' engagement in the learning process.