<![CDATA[General Background Contemporary education requires students to master 21st-century skills, including oral communication and critical thinking within student-centered environments. Specific Background This qualitative descriptive research analyzes the implementation of Problem-Based Learning to improve junior high school students' speaking skills through the topic of additive substances in English and science classes. Knowledge Gap Although Problem-Based Learning is widely recognized for improving speaking performance, research specifically integrating additive substance materials within a problem-based learning framework for junior high school students remains limited. Aims This study aims to analyze the implementation of Problem-Based Learning in improving junior high school students' speaking skills through additive substance topics and to identify challenges during the process. Results The findings indicate that the application of Problem-Based Learning successfully fosters contextual, creative, and student-centered learning, enabling students to show significant improvements in speaking fluency, vocabulary mastery, and self-confidence while cultivating preventive awareness against additive substances. Novelty This study demonstrates a dual-impact educational model that simultaneously integrates language competency acquisition and preventive character education through meaningful real-world problem investigation. Implications These insights suggest that educators should adopt Problem-Based Learning methodologies to foster critical thinking, collaboration, and meaningful communication aligned with independent curriculum principles. Highlights: Problem-Based Learning creates contextual, creative, and student-centered learning environments that actively engage learners. Students achieve noticeable gains in oral fluency, vocabulary retention, and self-assurance during presentations. Integrating health topics into language lessons builds social awareness and preventive attitudes regarding harmful substances. Keywords: Problem-Based Learning, Speaking Skills, English Language, Contextual Learning, Additive Substances]]>
