The purpose of this study was to investigate Vocabulary Learning Strategy (VLS) use of English Language and Literature Department students in relation to academic success and vocabulary size. The participants of the study are 213 English Language and Literature students. Two data collection tools were used in the study. The first tool was theVocabulary Learning Strategy (VLS) questionnaire which was adapted from by Gu & Johnson (1996), and the second data collection tool was a Vocabulary Level Test (VLT) developed by Nation (1983). Descriptive statistics were conducted in order to measure the level of vocabulary learning strategy (VLS) use and vocabulary size of the participants. In addition, correlation analysis was carried out in order to see which VLSs are more frequently used by low, middle and upper level vocabulary size students. The results indicated that the participants have a high level of vocabulary size for 2000 word level, 3000 word level, and academic word levels, a moderate level of vocabulary size for 5000 word level and a low level in 10000 word level. The participants were found to have a moderate level of vocabulary learning strategy use. The study also found that 3rd grade students had larger vocabulary size in terms of 2000, 3000 and academic vocabulary level. As for the vocabulary strategy use, 3rd grade students were found to use "bottom-up strategies" and "note-taking strategies" more frequently than 2nd grade students. Finally, correlation analysis revealed that "bottom-up strategies, using linguistic clues", and "top-down strategies" significantly correlated with academic success.