The use of electronic information resources (EIRs) by undergraduates could impact positively on their academic activities. However, anecdotal and empirical evidences have shown that the use of some of these information resources by some undergraduates is low. Perhaps, this perceived observation might not be unconnected with the effort expectancy associated with the accessibility of EIRs which could affect their use by the undergraduates. The study therefore examines effort expectancy as correlates of use of electronic information resources by undergraduates in Ajayi Crowther University, Oyo, Nigeria. Descriptive survey research method was used and the study population comprised of 5663 undergraduates of Ajayi Crowther University, Oyo, Nigeria. The multistage random sampling technique was used to select a sample size of 140 and the questionnaire was used to collect data. Results revealed that a significant number of respondents (45.3%) and (37.4%) noted that e-news and e-encyclopedias were the most accessible EIRs. Majority of the undergraduates had a favorable expectancy of the use of EIRs. Results showed a significant positive relationship between effort expectancy and use of EIRs by the undergraduates (r=.277**; df=138; p<0.01). It was recommended that in order to sustain the favourable effort expectancy towards the use of EIRs by the undergraduates, librarians should introduce periodic digital literacy programmes and ensure that all undergraduates are encouraged to participate in it.