The aim of the study is to develop a differentiation approach for the mathematics education of gifted middle school students and to determine the effect of the differentiation approach on creative thinking skills of gifted students based on both cognitive and affective factors. In this context, the answer to the following question was searched: "Is there any effect of the differentiation approach developed based on mathematics education of gifted students on the creativity of gifted students?" In the present study, in the scope of quantitative research the model of pre test-post test with control group was used. The sample of the study consists of 54 gifted students studying at 5th and 6th grade in a private school in Maltepe district of Istanbul. As a data gathering tool, Mathematics achievement test, Torrance Creativity test, Divergent Feeling test and multiple intelligence test were used. When the experimental group to whom the activities designed based on differentiation approach was applied compared with the control group, the creative thinking skills based on fluency, flexibility, originality and elaboration scores and creative thinking skills based on curiosity, imagination, risk-taking and complexity increased in a significant way. These results show that the developed differentiation approach increased the creativity of the students.