The use of the native language as a medium of instruction is believed to be the fastest and most natural route towards developing a strong foundation in mathematics literacy (Mimaropa, In D.O.No. 74, s.2009). This study examined the effect of using the native language in the teaching of kindergarten mathematics. A total of 34 five to six year old children went through a pretest-posttest, quasi-experimental study with 17 participants in each of the control or English group and the native language (Waray) or experimental group, respectively. It was assumed that the use of the native language would increase academic performance in mathematics. Findings revealed a highly significant difference between the mean gain of the control and experimental groups (p-value = 0.000) indicating that the level of mathematics performance of the experimental group was significantly higher than that of the control group. The result implies that the kindergarten pupils exposed to the native language performed better in mathematics than those who were exposed to English. The study concludes that the use of the native language in teaching kindergarten mathematics results in a higher mathematics performance than the use of a foreign language as a medium of instruction. (Contains 3 tables.)