This study investigated the roles of different executive function (EF) components (inhibition, shifting, and working memory) in 2-step arithmetic word problem solving. A sample of 139 children aged 8 years old and regularly attending the 3rd grade of primary school were tested on 6 EF tasks measuring different EF components, a reading task and a reading comprehension task, an arithmetic facts task evaluating basic knowledge of calculation, and three 2-step arithmetic word problems. Multiple hierarchical regression analyses were conducted to investigate the roles of the different EF components in the various phases of the problem-solving process. The results showed that EF affects the various phases of problem solving differently over and above calculation knowledge and reading abilities. The implications of these findings are discussed in relation to further understanding the role of cognitive skills in mathematical problem solving and in relation to instructional approaches that may increase children's performance on 2-step arithmetic word problems.