Digital library (DL) is an important information system which provides all-encompassing benefits to various stakeholders in scholarship and research through its provision of access to immediate and up-to-date information resources. The review of literature indicated low use of this system by engineering lecturers owing to system characteristics; and pay little or no attention to factors such as Performance Expectancy (PE) and Facilitating Conditions (FC) on the use of this system by engineering lecturers in universities. This study therefore investigated the influence of performance expectancy and facilitating conditions on the use of digital library by engineering lecturers in universities in South-west, Nigeria. Descriptive survey research design of correlational type was adopted. The study comprised 759 engineering lecturers in 10 universities in South-west Nigeria. Data analysis for the study involved frequency counts, percentages, mean and standard deviation were used for the analysis. Performance expectancy was found to be a critical factor in the use of digital library by engineering lecturers. The paper therefore, recommends the need for improvement of facilitating conditions such as provision of uninterrupted power supply, high Internet bandwidth and facilitation of periodic training in order to sustain the use of digital library by engineering lecturers in universities in South-west, Nigeria.