In this study, the influences of the activities that are prepared with the integration of science and mathematics on the critical thinking and scientific process skills of gifted middle school 6th grade students are investigated. In the study which is performed through the quantitative research method, single group pre- and post-test experimental design is used. In this respect, this is the first study that analyzes critical thinking and scientific process abilities of gifted people by experimental design, using the integration of science and mathematics, in Turkey. The study is performed with 6th grade students studying at a Science and Art Center in Central Anatolia in 2013-14 academic year. During the study that lasts almost 9 weeks, activities prepared through the integration of science and mathematics are applied to the students. Cornell Critical Thinking Scale Level X and Scientific process skills Test are employed used as pre- and post-test. Data are analyzed via a statistical software. In conclusion, it is explored that the activities which are prepared through the integration of science and mathematics have positive effects on critical thinking and scientific process skills of gifted students and within this scope some advices are presented for performers and researchers.