We explored the differences in academic achievement, personality, and cognitive factors among students who did and did not do extra credit. A total of 276 undergraduate students enrolled in introductory or upper-level psychology and biology courses were surveyed following their final exams to determine levels of academic self-efficacy, metacognitive ability, and a variety of other demographic factors. We conducted a 2 (Extra Credit: Completed or Not Completed) x 2 (Course Level: Introductory or Upper-level) x 4 (Final Course Grade: "A", "B", "C", or "D/F") between-subjects MANOVA with academic self-efficacy and measures of metacognitive ability as dependent variables. Our results indicated that Academic self-efficacy and Regulation of Cognition metacognition scores differed based on these factors. The implications for how course-specific feedback and improved awareness of metacognition can improve student achievement related to our findings and future research directions are discussed.