Considering the appreciated role that lexis plays in learning an additional language, research studies addressing vocabulary knowledge have attracted the attention of language teachers and researchers. The study of vocabulary learning strategies and how they relate to language learners’ vocabulary knowledge, therefore, is of immediate pedagogical as well as theoretical relevance. This study investigates the relationship between Iranian EFL learners' vocabulary learning strategies and their breadth (meaning recall and meaning recognition) and depth of vocabulary knowledge. To collect data, the Vocabulary Learning Strategies Survey, Depth of Vocabulary Knowledge Test, Meaning Recall Task and Vocabulary Level Test were given to two hundred and thirty (56 male and 144 female) English majors. Structural Equation Modeling was utilized to analyze the data and test the hypothesized model. Results indicated that strategies associated with direct individualized attempts (determination strategies) were significant predictors of both vocabulary breadth and depth knowledge and that mnemonic/memory strategies significantly predicted vocabulary breadth positively but depth negatively. Other strategies seemed to have different effects on various dimensions of vocabulary knowledge. The study has pedagogical implications for vocabulary learning and teaching.
