Social work practice requires that graduates be prepared to deal with complex, multifaceted problems which cannot be defined completely, do not have absolute, correct answers and can be approached from multiple perspectives. This study evaluated the influence of case-based instruction on MSW students' reflective judgment, an aspect of critical thinking associated with the ability to reason through ill-structured problems. (King, Wood, & Mines, 1990). The Reflective Judgment Model, which describes a developmental continuum based upon epistemic assumptions regarding the source and justification of knowledge claims, served as the theoretical framework for the assessment of reflective thinking in this mixed methods study. A quasi-experimental pre-post nonequivalent control group design was utilized to explore whether students who participated in a case method course demonstrated greater increases in reflective judgment than those who did not. MSW students enrolled in a case-based capstone course at a major metropolitan university in the southeast served as the intervention group, while foundation year students enrolled in a research methodology course served as the comparison group. Both groups completed the Reasoning about Current Issues Test (RCI), which is an online, standardized measure that has been widely used to assess reflective judgment (Wood, Kitchener, & Jensen, 2002) at pre and posttest. Content analysis procedures were used to facilitate assessment of students' initial and final case analysis papers for evidence of changes in the reflective thinking skills and problem-solving approaches utilized on initial and final case analysis papers. The case method participants' mean RCI scores remained unchanged between pre and posttest, while RCI posttest scores of participants in the control group decreased significantly. Pre and posttest comparison of students' case analysis papers using a customized rubric based on Wolcott's Steps for Better Thinking (2006) similarly indicated no mean changes in problem-solving approaches between pre and posttest. However, students who began the course using strategies associated with pre-reflective judgment increased their scores on the rubric significantly while those who exhibited higher levels of quasi-reflective judgment at pretest decreased at posttest. Strategies for designing a developmental curriculum to target the reflective judgment levels of MSW students are proposed.