International Journal of Scientific & Engineering Research, Volume 5, Issue 2, February-2014 910 ISSN 2229-5518 IJSER © 2014 http://www.ijser.org Effects of Mastery Learning Approach on Students’ Achievement in Physics Sunday A. Adeyemo, Ph.D, Veronica F.T Babajide, Ph.D Abstract This study investigated the effect of Mastery Learning Approach (MLA) on students’ achievement in Physics. Using stratified random sampling, a total of 160 Senior Secondary school II Physics students from four selected Senior Secondary Schools in Bariga and Somolu Local Government Areas of Lagos State was used for the study. Two research questions and hypotheses were formulated and tested respectively. The study was a non-randomized pre-test post-test control group design .Students in the experimental groups was exposed to MLA teaching method while those in the control groups were exposed to the Conventional Teaching Method (CTM). The instruments used in the study were Physics Achievement Test (PAT) to measure students' achievement and a questionnaire on 4- point scale was used to measure their attitudes towards Physics. The instrument were pilot tested;r value for PAT=0.7 using split half method and r=0.83 for questionnaire using Cronbach Alpha. T-test, Pearson Correlation and Analysis of Variance (ANOVA) were used in analyzing the data. The result showed that students exposed to MLA performed better than those taught using CTM. Also students with positive attitudes towards Physics performed better than those with negative attitudes towards Physics. Consequently, it is recommended that MLA should be encouraged in schools for improved students’ achievement and positive attitude towards physics. Key words: Mastery learning, physics achivement. IJSER