The purpose of the present study was to investigate the rhythmic ability of pre-school children engaging in motor activities accompanied or not by music. A total of 180 children (90 boys and 90 girls) at the age of 5±0.5 were randomly selected from kindergartens of Magnesia area-Greece to participate in the study. The High/Scope Rhythmic Competence Αnalysis Τest (Weikart, 1989) was used for the evaluation of rhythmic ability using 2 testing tempos: 120 and 130 beats. The 3-way ANOVA revealed that all children performed significantly better in lower tempo (p< .05) and girls performed better than boys (p< .05). The test scores were significantly different among the three activity groups (p< .05) with the best performance shown on the group of motor activities accompanied by music and then the group of motor activities without music. Girls in the first group (activities accompanied by music) significantly surpassed boys of the same group in both testing tempos. In conclusion, motor abilities accompanied by music, play an important role to the development of rhythmic ability. More research is needed on the effects of music on the development of children’s rhythmic abilities taking into account gender and maybe former movement repertoire.