This study synthesized and described the use of mother tongue in teaching Mathematics. It utilized qualitative research studies published in research journals from 2003-2017. With the criteria set for purposive sampling, ten (10) out of 33 qualitative research studies from different countries were incorporated and analyzed. From the comparison of the similarities and differences of the contents of these studies, themes were developed and analyzed. Findings revealed that teachers from primary schools were using mother tongue in the teaching of Mathematics. Teachers' attitude towards the usage of mother tongue in the delivery of teaching Mathematics contributed to students' Mathematics performance and attitude. Instructional materials were easier for teachers to develop and create using mother tongue. However, there were no sufficient financial funds for them to utilize to come with the desired learning resources. Several programs employing the use of mother tongue in teaching Mathematics benefited government provisions in terms of law crafted and implementation through trainings of teachers. The teaching Mathematics utilizing mother tongue can be effective through the effort and competence of the teachers with the government support to provide access and high quality Mathematics teaching and learning.