The present study aimed at investigating sources and consequences of Turkish middle school students' science self-efficacy beliefs. While mastery experience, vicarious experience, verbal persuasion, and emotional arousal were examined as sources of self-efficacy beliefs, students' achievement goals, metacognition, and effort regulation were examined as consequences of self-efficacy beliefs. Self-report instruments were administered to 1,932 middle school students to assess variables of the study. Results showed that mastery experience, verbal persuasion, and emotional arousal significantly predict students' science self-efficacy which was found to be positively linked to achievement goals, metacognition, and effort regulation. In addition, a positive relationship was found between verbal persuasion and mastery approach goals. Moreover, findings revealed that approach goals were positively associated with metacognition and effort regulation while avoidance goals are negatively linked to effort regulation. Additionally, results indicated a positive association between emotional arousal and effort regulation.