This study aims to evaluate the effectiveness of a blended training program for secondary school teachers in Vietnam that integrates Artificial Intelligence (AI) and Internet of Things (IoT) into STEM education. Using a quantitative research design, data were collected from 854 teachers through pre- and post-training surveys. Findings revealed a high level of satisfaction (Mean = 4.38/5) with the training content, delivery methods, and practical applicability. Teachers reported improved confidence in applying AI and IoT in lesson planning and implementation. This research highlights the feasibility of integrating emerging technologies into STEM teacher training in developing countries and underscores the importance of continuous professional development. The study provides policy implications for scaling such initiatives and recommends future studies on long-term impact assessment and student outcomes.