Clinical Question: Do school-age children with language learning difficulties who receive morphological-based intervention show improvement in word knowledge relative to a comparison intervention or control condition? Method: Systematic Review. Sources: ERIC, ASHAWire, PsycINFO, Linguistics and Language Behavior Abstracts (LLBA). Search Terms: language AND morph* AND intervention, therapy, teaching, instruction, Treatment. Number of Studies Included: 5. Primary Results: Children with language learning difficulties learn the meanings of morphemes that are directly taught during morphological-based intervention. Children with language learning difficulties who receive morphological-based intervention show generalization of taught derivational morphemes to untaught words. Children with language learning difficulties have shown clinically significant improvement on standardized vocabulary tests following morphological-based intervention. Conclusions: An overall aim of a morphological-based vocabulary intervention is for students to strategically apply their knowledge of derivational morphemes and root words to predict meanings of unknown morphologically complex words. There is high-level evidence supporting the effects of morphological-based instruction on vocabulary for typically developing children. However, additional research is needed to firmly establish the effectiveness of morphological-based strategies for the population of students with language learning difficulties. For these students, there is minimal evidence (primarily case and single-subject studies) that supports incorporating morphological-based strategies as one component within a comprehensive vocabulary intervention program. Additional research is needed to determine the effectiveness of morphological-based approaches compared to other vocabulary approaches.