Purpose – The purpose of this paper is to evaluate the quality of online services in academic libraries in Nigeria. It seeks to assess the functionality of electronic infrastructures, to expose areas where the service needs of users are not adequately provided and to recommend solutions. Design/methodology/approach – The sample population was 210 staff and students who used electronic resources in Nigerian university libraries during the 2012-2013 academic session. A questionnaire was the main instrument for data collection. Modified WebQual four performance indicators were designed and used to measure: library equipment, library website, online public access catalogue (OPAC) and e-user education in the university libraries. The five-point service performance scale that ranged from very poor performance to excellent was used in measuring the views of the respondents. Findings – None of the indicators was rated excellent; six were rated good; nine were average; two and five indicators scored poor and very poor, respectively. Poor funding, intermittent power supply and weak telecommunication infrastructures were among the major impediments to online services in Nigerian universities. Through adequate funding and prudent management of library funds, online services in Nigerian university libraries could meet global standards. Practical implications – Results from this paper could guide library management on several concrete remedial actions to sustain e-service performance that could meet the missions and visions of contemporary academic libraries. Originality/value – This paper was the first to apply WebQual model in the evaluation of electronic performance quality of academic libraries in Nigeria.