This study examined Vietnamese lower secondary English as a foreign language (EFL) teachers’ beliefs and self-reported formative assessment practices in writing instruction. Ninety-seven public-school teachers completed an adapted and extended bilingual questionnaire covering Beliefs, Monitoring, and Scaffolding. Responses showed high endorsement across Beliefs (M = 3.40, SD = 0.42), Monitoring (M = 3.39, SD = 0.43), and Scaffolding (M = 3.35, SD = 0.51), with high internal consistency (α = .940-.975). Preliminary factor analysis only partially reproduced the intended three-domain structure. The three domains were strongly and positively associated. Teacher guidance was endorsed more strongly than learner-directed goal setting, while digital/AI-supported practices received slightly lower ratings than the highest-rated conventional practices. The findings indicate alignment among teachers’ reported beliefs and practices, rather than direct evidence of classroom enactment. Professional learning should prioritize manageable evidence-to-action routines, learner agency, and critical use of technology-supported feedback in EFL writing.