The present study investigates and compares the influence of teaching Realistic Mathematics on the development of mathematical competence in kindergarten. The sample consisted of 231 Greek kindergarten students. For the implementation of the survey, we conducted an intervention, which included one experimental and one control group. Children in the experimental group were taught Realistic Mathematics according to the principles of Realistic Mathematics Education. The control group was taught mathematics following the basic pedagogical principles of curriculum for kindergarten students. In order to evaluate the mathematical performance of children we used the Test of Early Mathematics Ability (TEMA-3). The results showed that the teaching technique with the use of Realistic Mathematic Education contributed significantly to the development of mathematical competence of young children. Moreover, factors such as gender, age and nonverbal cognitive ability, did not seem to differentiate the development of mathematical competence of children.