The purposes of the study presented in this article were twofold. One was to respond to the question: what makes a quality curriculum? within the framework of the fourth United Nations Sustainable Development Goal (SDG 4). The other was to develop and pilot an appropriate instrument to evaluate the quality of curricula in a sample of private schools in Vietnam. While public schools are still preparing for implementation of Vietnam's New General Educational Curriculum, small adjustments are already being made to the curriculum in some private and international schools in Vietnam, which have been issued a curriculum customisation licence. Therefore, the pilot schools which participated in this study can serve as case studies for the upcoming major policy improvement in Vietnam's public schools, thus providing guidance for Vietnamese policymakers, school principals and teachers. While there is no "one-size-fits-all" curriculum assessment formula, since each country exhibits distinctive features in its teaching and learning programme, the indicators developed by the authors for their study can be adjusted to suit the needs of other countries.