São Tomé and Príncipe is a multilingual country with diverse languages spoken by its population, including Portuguese as an official language and several indigenous languages. An action research study was conducted involving interviews with educators, parents, and students, as well as a review of existing policies and curriculum documents. Findings indicate that incorporating indigenous languages in early childhood education led to improved language acquisition skills among preschool children (85% showed significant improvement). Language policy plays a crucial role in shaping educational outcomes in multilingual contexts, particularly for young learners who benefit from bilingual or multilingual learning environments. Multilingual education should be prioritised to enhance language acquisition and literacy skills among children in São Tomé and Príncipe.