Social problem-solving (SPS) skills represent an individual's ability to effectively solve daily problems. Although previous studies have demonstrated the positive effects of SPS interventions, there is still a lack of evidence on the relevant moderating factors. Therefore, this study investigated the impact of an SPS intervention on a sample of elementary school children, by focusing on the potential moderating effects of executive function. The participants included a total of 101 fifth graders (mean age of 10.6 years), who were divided into two groups for an immediate intervention (treatment) and delayed intervention (control). The following three aspects were measured pre- and postintervention: SPS skills, emotional regulation, and school adjustment. Preintervention, we measured two aspects of executive function using the Cambridge Neuropsychological Test Automated Battery, including working memory and inhibition. Following the intervention, the participants increasingly generated alternative solutions, which may have contributed to better adaptive functioning and solutions. However, we also observed some negative impacts on participants with lower executive functioning, including deteriorating effects on emotional regulation (problem solving) and life satisfaction. These findings emphasize the need to pay close attention to the individual profiles of the recipients to design more effective interventions.