BACKGROUND: Appropriate complementary feeding practices (CFPs) play a key role for ensuring optimal health, growth and development for children 6-23 months. The purpose of this study was to determine the prevalence and associated factors of CFPs of mothers or primary caregivers having children 6-23 months in Thanh Phu rural district of Ben Tre province, Vietnam. METHODS: Three hundred fifty eight child-mother pairs participated in a cross-sectional study. Weight and height of children were measured by trained nutritionists using standard measurement tools and procedure. Mothers or primary caregivers were interviewed about maternal, child, and household characteristics, awareness of the food environment, household food insecurity (HFI), and CFPs using a structured questionnaire. Chi square test, Fisher exact test, t-test, and multivariate logistic regression were used to evaluate associations between CFPs and independent variables. RESULTS: The percentages of children with appropriate minimum dietary diversity (MDD), minimum meal frequency (MMF), and minimum acceptable diet (MAD) were 71.5%, 40.8%, and 31.6%, respectively. MDD was negatively associated with younger child, the child's sickness in the last 2 weeks, caregivers being fathers, not breastfeeding, lower monthly household income, and use of untreated drinking water after controlling for covariates (p <
0.05). Factors associated with poorer MMF included older child, not breastfeeding, and maternal biological status. Conversely, purchasing foods at the street vendors and appropriate MDD was positively associated with better MMF (p <
0.05). Maternal biological status, marital status of mothers, breastfeeding, and HFI were all associated with MAD (p <
0.05). CONCLUSIONS: These results revealed that inappropriate complementary feeding practices among children aged 6-23 months in rural disadvantaged areas of Southern region remained a significant challenge for nutrition improvement of young children in Vietnam. Child age, HFI, use of untreated drinking water, lower monthly income, mother's marital status, not breastfeeding, and source of purchased foods were associated with poor CFPs. Solutions for improving CFPs for children should address these underlying causes.