Decision making and problem solving skills are two important issues resulting with students' academic achievement. The aim of this research was to examine the relationship between primary school students' decision making skills and problem solving skills. The sample of research, which was carried out through relational survey model, consisted of 331 third and fourth grade primary school students in Istanbul. Data were collected through "Problem Solving Inventory for Children" and "The Scale of Decision Making Skills for Primary School Students". The research data were analyzed with descriptive statistics, Pearson Correlation analysis and simple regression analysis. According to the results of correlation analysis, it was determined that there was a positive significant relationship between decision making skills and problem solving skills of primary school students. It was concluded that decision making skills of students were significant predictors of their problem solving skills. As a result, it is seen that students' decision making skills affects problem solving skills moderately and positively.