In the preschool period, socio-dramatic play in particular supports children's meta-cognitive skills, such as problem-solving, reasoning, and mathematical skills. It is therefore essential to examine the relationship between socio-dramatic play and mathematical skills. The first purpose of this study, which focuses on the mathematical skills of six-year-old children enrolled in early childhood institutions, is to determine the mathematical skills and aspects of socio-dramatic play. The second purpose is to investigate the relationship among children's mathematical skills, demographic characteristics, and aspects of socio-dramatic play. The results revealed statistically significant differences in mathematics achievement scores of low- and middle-income family children, and children who played at the higher and lower levels of symbolic agent, symbolic substitution, and symbolic complexity. (author abstract)