The purpose of this investigation was to explore possible relationships between Socioscientific Issues instruction and students' development of reflective judgment. The usefulness of the Reflective Judgment Model as a tool for assessing the value of SSI is established in the parallels that can be drawn between them. Both involve ill-structured problems requiring evidence-based reasoning subject to differing interpretations by students, and both require examination, analysis and the blending of scientific and normative evidence, as students use that evidence to support a reasoned position. Results demonstrated both qualitative evidence revealing more sophisticated and nuanced epistemological stances toward higher stages of reflective judgment, as well as statistically significant gains within treatment groups with a moderately large effect size. Theoretical implications for advancing students' epistemological beliefs about evidence-based argumentation and pedagogical implications for rethinking how to connect science with topics that are fundamentally meaningful to students are discussed. (Contains 4 tables and 1 figure.)