The aim of this study was to investigate the association between mixed-SES kindergartens and emergent literacy in Italian children. The independent contributions of parents’ occupational (SES-PO) and educational level (SES-PE) on emergent literacy were separately analysed. Three emergent literacy skills were assessed in 189 children twice, at the beginning and the end of the last year of kindergarten. Firstly, repeated-measures MANCOVA has shown that only SES-PE was significantly associated with the increase of all emergent literacy skills over the school year. Secondly, robust-methods ANOVA has shown what type of mix of family-PE is optimal at a school level for children to achieve significant improvements after one year of kindergarten. Creating mixed-SES learning environments may improve children’s emergent literacy skills. Policymakers should specifically target parental educational levels, rather than occupational levels, when addressing the issue of SES in schools.