Learning in a child's mother tongue is crucial for enhancing critical thinking, the skills to learn a second language, and literacy skills. Since 2009, the Ministry of Education and Training (MOET) in Vietnam increased its focus on early childhood education through curriculum renovation, providing facilities and establishing teacher policies. Over the past decade, a rapid increase in access among 3- to 6-year-old children has been achieved, with a current enrollment rate of 99% for 5-year-olds. More vulnerable and disadvantaged children, such as those from remote and ethnically diverse districts, are being reached. This article examines one program, the Mitigating Preschool Children's Barriers to Learning in Disadvantaged and Ethnically Diverse Districts in Central Vietnam (2017- 2021), a collaboration of VVOB, a Belgian non-profit organization, and its partners, the Department of Education and Training (DOET) of three central provinces in Vietnam (Kon Tum, Quang Nam, and Quang Ngai), works on mitigating preschool children's barriers to learning in disadvantaged and ethnically diverse districts.