The present study aims to explore the knowledge level and preferences regarding vocabulary learning strategies (VLSs) among the EFL university students studying English for Specific Purposes (ESP) courses. It also investigates the impact of vocabulary learning strategies on EFL learners' performance. A sample of twenty students from an intact class participated in the study. For data collection, a triangulated approach has been employed through the usage of a questionnaire, semi-structured interviews, together with classroom observations. Moreover, the cumulative percentage of scores in the pre-tests and post-tests has been incorporated to investigate the impact of vocabulary learning strategies. SPSS software is used to calculate the T-test value. The findings demonstrate that the implementation of various vocabulary learning strategies has a substantial impact on the performance of the English language learners within the context of an English for Specific Purposes classroom. The findings have pedagogical implications in the teaching and learning of vocabulary within the ESP context.