This study analyzed the relationship between academic self-efficacy and academic performance among university undergraduate students. The study was conducted to attest the relationship and differences between academic self-efficacy and academic performance among university undergraduate students. The sample was drawn from two universities (public and private) on which the questionnaire to measure academic self-efficacy and the Cumulative Grade Point Average (GPA) was distributed to participants (140 females and 153 males) selected from three faculties (Education, humanities, science) using stratified sampling. The universities were selected purposively. Descriptive and inferential statistics were used to analyze the differences and relationship between academic self-efficacy and academic performance among university undergraduate students. The results obtained revealed that there is a statistically significant relationship between academic self-efficacy and academic performance among university undergraduate students (r (293) = .816, p < .01). There were differences noted as regards gender in the students’ academic self-efficacy (t (291) = 2.76, p < .01), and academic performance (t (291) = 1.56, p < .05). From the results of this study it is recommended that universities institute measures to enhance students’ academic self-efficacy as it has been noted that it is related to their academic performance.