The purpose of this study was to explore the values underlying the decision-making processes in group studies for Turkish and German mathematics teachers. This study presented a small part of a wider study investigating German and Turkish mathematics teachers' and their students' values (Values in Mathematics Teaching in Turkey and Germany [VMTG]). The study was conducted with 9 Turkish and 13 German mathematics teachers who were selected with purposeful and theoretical sampling. Semi-structured interviews and field notes were used as data collection instrument. Data were analyzed through constant comparative method. Results revealed four different major categories: (1) productivity, (2) socialization, (3) flexibility/authority, and (4) gender differences. Based on the findings, discussion, further recommendations, and implications were given at the end of the study.