Children with poor emotion regulation skills during early childhood may experience difficulties in coping with socio-emotional problems in later life. Therefore, interventions focusing on emotion regulation are of critical importance. The aim of this study is to examine the effects of a Cognitive Behavioral Play Therapy (CBPT)-based emotion regulation psychoeducation program, developed for children in early childhood, on their social skills. The study was conducted using a mixed-methods design; a quasi-experimental design with a pretest-posttest control group was employed in the quantitative phase, while a phenomenological design was used in the qualitative phase. The study sample consisted of eight preschool students aged five; the students were randomly assigned to experimental (n = 4) and control (n = 4) groups. A structured psychoeducation program consisting of six sessions and incorporating CBPT techniques was administered to the experimental group. No intervention was applied to the control group. Additionally, two group interviews were conducted with the mothers of the children in the experimental group while the experimental process was ongoing. The quantitative findings indicated that the implemented psychoeducation program had statistically significant and positive effects on the children's social skills. The qualitative data revealed that the children developed emotional awareness, made progress in emotion regulation and problem-solving skills, and exhibited positive changes in their skills for establishing and maintaining friendships. The findings suggest that a structured emotion regulation psychoeducation program integrating CBPT techniques has the potential to support socio-emotional development in early childhood.