This study investigated how middle school students leverage information about bound Latin roots (e.g., voc in "advocate" and "vociferous") to infer meanings of unfamiliar words, and how instruction may facilitate morphological analysis using roots. A dynamic assessment of morphological analysis was administered to 29 sixth graders (n = 17 intervention students) and 30 seventh graders (n = 18 intervention students). Qualitative analyses of analytic strategies revealed patterns of morphological problem solving that included "direct" (i.e., direct application of roots to analyze unfamiliar words) and "indirect routes" (i.e., use of known words that carry the roots to analyze unfamiliar words). Intervention students applied a direct route at higher rates than control students. Correlational analyses revealed a small but significant treatment effect on establishing meaning memory representations for roots and a significant, positive treatment effect for use of roots to infer unfamiliar word meanings. Overall results show promise for use of bound Latin roots for morphological problem solving. [This article was published in "Cognition and Instruction" (EJ1093957).]