When learning merges with technology, it creates an e-learning environment. Such environments integrate with software applications and create e-books for the beneficiaries who register with the system. This study aimed to investigate the determinants of e-book usage by Undergraduates in the Faculty of Commerce and Management Studies, University of Kelaniya. Three hundred thirty-five undergraduates from the Faculty of Commerce and Management Studies, University of Kelaniya, were used as the sample. Data were collected through a standard questionnaire distributed via a google form. Version 23.0 of the Statistical Package for Social Sciences (SPSS) was used to analyze the data. The mean score and standard deviation for each variable were utilized for univariate analysis, and the correlation coefficient was employed for bivariate analysis. The regression and Sobel tests were used to test the hypotheses. The results revealed a significant impact of Perceived Ease of Use and Perceived Usefulness on E-book usage that has been significantly mediated by Behavioural Intention to Use. These findings have consequences for educators and instructional methodologists, who must balance the benefits of new learning technology with the realities of student perceptions and use.