This study examined “effects of e-library on students’ academic performance in tertiary institutions: a case study of Ahmadu Bello University, Zaria” It identifies the Concept of e-library and e-resources, availability of e-library, resources and services in Nigerian tertiary institutions. Students’ use of e-library in Ahmadu Bello University, Zaria, impact of e-library on students’ academic performance, challenges associated with the utilization of e-library resources in Ahmadu Bello University, Zaria. The research method used in this project is survey research method. In a survey method, questionnaires are the main instrument for data collection. Frequency tables and percentages are the main tools used for data analysis. Results of the analysis showed that e-journals e-dissertations, e-projects and e-theses, full text databases, institutional repository are the types of e-resources available in the mtn/undergraduate e-library in Ahmadu Bello University, Zaria. Current Awareness Services is the only service available in the e-library of Ahmadu Bello University, Zaria. Students’ always use the e-library. Poor information technology infrastructure, lack of knowledge on how to use e-resources, large mass of irrelevant information, high cost of access to some resources, download delay or low internet connection and lack of search skills are the challenges associated with the utilization of e-resources. Recommendations were proffered and some of the recommendations are: the management of the library should provide more services like selective dissemination of information to support the current awareness service available. Since it’s on record that students always use the mtn/undergraduate e-library of Kashim Ibrahim Library of Ahmadu Bello University, there should be a policy for the development of relevant e-resources to promote accessibility and utilization.Effects of e-library, resources and services on students' academic performance in tertiary institutions a case study of Ahmadu Bello University, Zaria.