The study examined the effect of instructional simulation strategy on learning outcomes of secondary school students in Biology in Ondo State, Nigeria. The study adopted quasi – experimental pre-test and post-test two group design (experimental group and control group) research design. The targeted population for the study consisted of all the Senior Secondary School (S.S.S.) one students in public secondary schools in Ondo State. The sample consisted of 134 S.S.S. 1 students (class intact size) drawn from six public secondary schools in Ondo State. The sample was selected using multistage sampling procedure. Two research instruments namely Biology Achievement Test (BAT) and Questionnaire on Students’ Interest in Biology (QSIB) were used to collect relevant data for this study. The face and content validity of the instruments were ensured by experts in Tests and Measurement and Biology Education. The reliability of the instruments was established using internal consistency method which yielded reliability co-efficient values of 0.74 and 0.78 for BAT and QSIB respectively. The data collected for this study were analyzed using descriptive and inferential statistics. The findings of the study revealed that the two groups (instructional simulation strategy and conventional method) were homogeneous at the commencement of the experiment. The use of instructional simulation strategy and conventional method enhanced performance and interest of students in Biology while instructional simulation strategy is the more effective. It was recommended among others that the use of instructional simulation strategy should be encouraged in Biology class in secondary schools so as to enhance better academic performance and interest of students in Biology. Keywords: Instructional Simulation Strategy, Learning Outcomes, Biology, Students,

This article has been published at SPECIAL ISSUE, www.easij.com, Issue: 2, Volume: 2, August 2020.