Purpose: This study aimed to discuss college students' creative mathematical thinking in open-ended problem solving. In particular, this study would attempt to characterize the differences in students' creative mathematical thinking skills based on cognitive styles.

Research Method: This study employed a descriptive qualitative design. The population of this study consisted of 105 pre-service elementary school teachers who were enrolled in the fifth semester classes at Universitas Muhammadiyah Makassar. Open-ended problem solving sheets and interview guidelines were developed as the instruments to measure the students' creative mathematical thinking. Meanwhile, to group students based on their cognitive styles, Group Embedded Figure Test (GEFT) was conducted. The students were categorized into field independent (FI) and field dependent (FD) students.

Findings: In general, the results reported that both the FI and FD students could perform all the aspects of creative mathematical thinking (flexibility and fluency) in solving open-ended problems. However, unlike the FD students, the FI students were able to generate more various and unique ideas (more flexible) because they possessed higher spatial reasoning skills. On the other hand, despite mistakes in calculation, the FD students always did an evaluation quickly and fix the answers as soon as possible (fluency).

Implications for Research and Practice: The implications of the current study were addressed to educational practices, especially at the tertiary level. In addition, the results of this study also provide an insight for the development of mathematical creative thinking assessment or evaluation tools.