In an effort to increase students' informed decisions and evidence-based argumentation and perspective taking in the STEM classroom, this case study explored the ways in which teachers' thinking and intention of incorporating Socioscientific Issues (SSI) into their lesson plans change after participating in an experiential workshop. Recognizing the difficulties inherent in SSI implementation, the day-long teacher development implemented a multi-layered approach which included declarative and procedural knowledge construction, namely understanding SSI components, SSI lesson planning, and learning STEM topics through the SSI framework. Pre-post conference questionnaires and lesson analysis showed that teachers were adept in developing SSI-focused lessons. In addition, the majority of teachers who had not previously taught an SSI lesson, did intend to develop SSI lessons in the future which included scientific phenomena or system dynamics. Implications for STEM teacher development are discussed.