This study evaluated the effectiveness on the use of Mother Tongue in teaching the concepts of fraction among second grade of elementary school pupils. It adopted a pre-test post-test quasi-experimental design with 82 pupils in the second-grade elementary school as samples. The test from the District Office of the Department of Education was used to collect data from the subjects. Data collection tools using pre-test and post-test evaluation, with using SPSS for data analysis. Findings showed that the use of Mother Tongue Language (MTL) is more effective than the Non-MTL in teaching the concepts of fractions. It resolved that MTL could be used as the medium of instruction in teaching lessons in grade two. It recommended that relevant and updated instructional materials be available to carry out effective teaching-learning process.