Early childhood education (ECE) is crucial for children’s cognitive, socio-emotional, and behavioural development, yet evidence on adapting international curricula to Central Asia is limited. This study evaluated an adapted version of Singapore’s Nurturing Early Learners (NEL) framework for preschoolers aged 6–7 in Uzbekistan, incorporating Uzbek-language materials, culturally relevant scenarios, and a safety and emergency preparedness module. A quasi-experimental pretest–posttest design involved 56 children from two comparable preschools, evenly assigned to an experimental (EG) and a control group (CG). The intervention’s causal effect was assessed using a Difference-in-Differences (DiD) model, complemented by thematic analysis of classroom observations, teacher journals, and interviews. Results showed significant improvements for the EG in cognitive (β = 0.41, p < 0.01), socio-emotional (β = 0.37, p < 0.05), motor (β = 0.44, p < 0.01), and safety skills (β = 0.52, p < 0.001). Qualitative data confirmed increased engagement, cooperation, and procedural safety understanding. The study demonstrates the adapted NEL framework’s pedagogical effectiveness and cultural appropriateness, providing guidance for curriculum reform and teacher development in Uzbekistan.