Aim: The study described diabetes self-management (DSM), diabetes knowledge, family and friends’ support, healthcare providers’ support, belief in treatment effectiveness and diabetes management self-efficacy, and explored DSM’s associations among Vietnamese adults with type 2 diabetes mellitus (T2DM). Design: A cross-sectional design was applied. Methods: The study used self-report questionnaires to collect data from 198 participants. Descriptive statistics and structural equation modelling (SEM) was used for data analysis. Results: Vietnamese adults with T2DM performed DSM limitedly in certain aspects. They had strong belief in treatment effectiveness, good family and friends support, limited diabetes knowledge, healthcare professional support and self-efficacy. Their DSM was directly associated with diabetes knowledge, family and friends’ support, healthcare providers’ support, belief in treatment effectiveness and diabetes management self-efficacy. Their DSM was indirectly associated with diabetes knowledge and family and friends’ support through their belief in treatment effectiveness and diabetes management self-efficacy.