This Study aims to determine the pupils mathematics performance using mother-tongue approach. The study was conducted on the third week of November 2015. The participants in the study were the sixty-five grade III pupils from the public elementary school in the province of Iloilo. The data gathering instrument used was a researcher made-test based on the first grading lessons. The statistical tool used were mean, standard deviation and Spearman's rho test. The result showed that there was a significant relationship between pupils test score in mathematics using mother-tongue approach and Mathematics grade(r=.64, p=.00). This implies that test score in mathematics using mother-tongue approach was positively correlated with mathematics grades. It means further that, pupils mathematics grade can be traced with their understanding in mathematics using mother-tongue approach. The results of this study supports the claims of Kosonen (2005), that the advantages of a mother tongue right from the start: children are more likely to succeed. Research also suggest that engaging marginalized children in school through mother-tongue based, multilingual education is a successful model.