Musical preferences are an extremely complex phenomenon formed under the influence of many factors. The paper investigates whether there are gender- and age-related differences in the preferences of primary school students from Croatia and Bosnia and Herzegovina and whether there is a connection between music familiarity and preferences for certain musical excerpts. To examine students’ preferences for musical excerpts, a general data questionnaire and an assessment scale were administered to a sample of 253 participants, including second, third, seventh, and eighth grade primary school students from Croatia and Bosnia and Herzegovina. The results show gender- and age-related differences in the preferences for classical music, whereby female students, compared to male students, and younger students, compared to older students, show higher preferences for classical music. A significant interaction effect of gender and age on classical music preferences was found. Furthermore, the results show that male and female students do not differ in their preferences for world music, while age-related difference was observed, with younger students, compared to older students, showing greater preferences for this musical style. A significant interaction effect of gender and age on world music preferences was found. Finally, it was confirmed that students show higher preferences for familiar musical excerpts compared to unfamiliar musical excerpts. The obtained results represent a significant contribution to the study of musical preferences from the aspect of music psychology and music pedagogy.