Iyekolo, A. OlusholaAjibola, B. CAhmed, M.B2019-10-302019-10-302019-061116-0381http://hdl.handle.net/123456789/3182This study examined the influence of class size on junior secondary school students performance in Ilorin South Local Government Area. Also it investigated whether class size had influence on academic performance of students in on the basis of gender and school types. Descriptive research of survey type was adopted in this study. Sample of 200 respondents was drwan for this study. The instrument used to gather data for the study was Performance Test Pack (PTP) adapted for use from the junior questions. Demographic data of the respondents were analysed using simple counts and percentages while the hypotheses formulated were tested using inferential statistics of t-test at 0.05 alpha level. This study concluded that students in normal class size performed better than their counterparts in large class size. It also showed that class size has influence on academic performance of students on the basis of gender and school type. Male students performed better than female students while private school students performed better than their public school counterparts. It was therefore recommended that: the state government should endeavour to implement and monitor studnents-teacher ratio, school management should endeavour to create an enabling environment that will enhance learning for both sexes and government should increase her monitoring of school for teachers to put in their best.enClass SizePerformanceArticle