Limited research on the PYLT (productive Vocabulary Levels Test) stimu lated the investigation into the relationship between the PYLT and Korean col lege students' productive vocabulary use in writing. For the purpose of the study, twenty five students (n=25) were asked to take the PVLT, perform translation tasks, and write an essay. They were also asked to write a reflection paper to examine their perceptions of the PVLT. The LFP (Lexical Frequency Profile) was employed to analyze the students' compositions to examine the relationships between their vocabulalY profiles and the PVLT. The results of the study indicated that there was no significant correlation between the PYLT and the LFP; the relationships between the PVLT and other variables were largely influenced by word frequency levels. These findings imply that the PVLT at the 2000 word frequency level represents the students' vocabulary knowledge in their compositions, and their writing proficiency. As for the perceptions of the PYLT, most of the students responded that the PVLT assessed their vocabulalY knowledge. Interestingly, they attributed both success and failure in providing correct answers to the test format of the PVL T. This study suggests that interpretation of the results of the PYLT should be associated with word frequency levels.