This study investigated the impacts of using ethnomathematics in teaching on performance and retention in mathematics among primary III pupils in Lere education district, Kaduna State, Nigeria. The study was conducted based on four specific objectives. Four research questions were constructed and four null hypotheses were formulated to guide the study. A pre-test, post-test and post-posttest quasi experimental design was adopted. From a target population of two hundreds and ninety five 295 public primary Schools with 11,289 pupils (5,862 males and 5,427 females) simple random sampling techniques were used to select the schools and the class of the pupils respectively. 207 pupils were selected for the study in accordance with Central Limit Theorem that regarded a minimum of 30 sample size appropriate for experimental research. Mathematics Performance Test 1 (MPT1), Mathematics Performance Test 2 (MPT2) and Mathematics Retention Test (MRT) were the instruments used in collecting data as Pretest, Posttest and Post-posttest respectively. A Spearman-Brown coefficient of r = 0.89 was found. The data were analyzed using mean, standard deviation and t-test Analysis at 0.05 level of significance using statistical package for social sciences (SPSS),version 2016.Results of the study indicated that primary III pupils taught using ethnomathematics teaching performed and retained mathematical concepts better than those taught with conventional teaching method. The result also revealed no significant difference between the performance and retention of male and female primary III pupils taught mathematical concepts using ethnomathematics teaching strategy. The study revealed among others that ethnomathematics teaching strategy was gender friendly. The study recommended among others that mathematics teachers should endeavor to use ethnomathematics in teaching primary III pupils for better performance and retention of mathematical concepts in our primary schools. The results of the findings of the study suggests for further studies in different location of the country(Southern Nigeria). The findings of the study will benefit the mathematics educators, mathematics students , curriculum planners, government and non-governmental organizations among others