A significant way to contribute in the analysis of deficiencies in school performance, a known issue particularly in mathematics, is by delving into children's development of informal mathematics during their early childhood, and thus have better elements to intervene in a more timely, effective manner. From this point of view, this study analyzes how the relationship between parenting behavior and early mathematics can be mediated by the development of self-regulation in children. The sample of the study is made of 85 students, between 5 and 6 years old, who are in their last year of preschool in two public schools in Lima. The instruments used are the Spanish translations of the Test of Early Mathematics Ability--3, Head-Toes-Knees-Shoulders task and Parent Behavior Inventory. The main results show that self-regulation in children and their caregivers' parenting behavior are significant predicting variables in early mathematical development. Specifically, the findings suggest that self-regulation in children can significantly mediate the relationship between the dimension of support/engagement in parenting behavior and the development of early mathematics in children during preschool.