This study focused on the influence of self-efficacy on e-library usage by undergraduates of a Nigerian university. One hundred and fifty copies of questionnaire were administered with 87.3% returned for analysis. The study revealed that undergraduates make use of the e-library (70.2%) mainly for journal search (55.7%), textbooks search (58.8%) and research topic search (43.5%). Also, at 0.05 level of significance, undergraduates’ self-efficacy has influence on their e-library use (F=0.387, df=2, P=0.542) and there is a significant positive relationship between students’ self-efficacy and e-library use (F=0.778, df=2, P=0.461). It was recommended that quality e-resources should be acquired by the library and provided for use without any form of restrictions and state of the art e-resources should be procured and easily accessible for use of the undergraduates like their postgraduate counterparts.