Bandura's (1997) self-efficacy theory posits four principal sources of information (i.e., performance accomplishment, vicarious experiences, verbal persuasion, and physiological states) through which individuals acquired and modify their self-efficacy beliefs. The objectives of the present study were to examine the predictive and mediational role of self-efficacy and the order of potency of the four sources of information for English, mathematics and science. Six structured multiple-choice questionnaires and an achievement test were administered to primary school students in 5th and 6th grades (N=272). Path analysis techniques were used to infer direct and indirect effects of the four sources of information on self-efficacy, and self-efficacy on performance. The findings are consistent with previous findings and confirm Bandura's order of potency of the four information sources. However, not all four sources of information were predictive of self-efficacy. For each subject, self-efficacy beliefs mediated the effects of the four sources on performance. As well, English and science self-efficacy beliefs were predictive of students' English and science performances respectively. Except for mathematics anxiety, ANOVA results revealed no significant univariate effects for gender. Based on the findings, educational implications are discussed with several caveats and directions considered.