In the process of education the knowledge is acquired which is a necessary base for creativity. The problem of relations between creativity and knowledge in school context is posed as a problem of relations between creativity and academic performance due to the influence it has on personal and professional development of an individual. The paper presents the results of survey on relations between creativity, academic performance and academic preferences. Creativity was measured by the test for creative thinking - drawing production of Urban and Jellen, academic performance by general achievement, and academic preferences by a questionnaire. The sample comprised final primary school graders. Low and statistically significant positive correlation was found between creativity and school achievement in the sub-sample of girls. However, girls have a significantly better school achievement and prefer art as a school subject and the test administered demands visual art expression. Hence, it can not be claimed for sure that the obtained results reflect realistic differences in creativity between boys and girls. It is of vital importance for work in school the data that high creativity can be possessed by students who are failures at school. It has been concluded that initial step in the acquisition of knowledge that will contribute to student creative thinking and behavior is the development of cognitive flexibility.