The evaluation of mathematical thinking in science and mathematics groups is important because it shows the necessity of science-mathematics integration in programs. The aim of this research is to determine the mathematical thinking levels of the teacher candidates who are studying in Mathematics and Science fields and to show whether there is a difference between them. The study was a quantitative research conducted in survey model and the "Mathematical Thinking Scale" was used to determine the mathematical thinking levels of the teacher candidates. The scale of the five-point Likert type consists of 25 items, 20 positive and 5 negative. It has four sub- dimensions: high-level thinking, reasoning, mathematical thinking skills, and problem solving. The working group constitutes 208 teacher candidates who are educated in the Department of Mathematics Education and Science Teacher Education of the Education Faculty of two different universities in Marmara region. In this study, which determines the level of mathematical thinking and whether there is a meaningful difference between the levels, a difference emerged in favor of mathematics teacher education students. While there was a significant difference in subscales of mathematical thinking in terms of high level thinking, reasoning and total scores in the research, no significant difference was found in problem solving and mathematical thinking scores. It is proposed that the integration of mathematics and science should be arranged in such a way that students can see their mathematical applications in real life and that the teaching environments in which teacher candidates' mathematical thinking skills are conscious of their activities are suggested.