This research examined the effectiveness of three different learning strategies on Korean EFL students' vocabulary comprehension and retention: context, semantic mapping, and word lists. 116 college freshmen were placed into one of the three treatments of vocabulary instruction. Subjects were tested on varying levels of vocabulary knowledge using three different tasks (definition test, multiple-choice test, and fill-in test) immediately following and two weeks after instruction. Regarding the tasks checking vocabulary comprehension, significant difference was not found across the three treatments on the definition test. Subjects under the context treatment, however, significantly outperformed subjects under the word list treatment on the multiple-choice test and also scored better than subjects under the word list and under the semantic mapping treatments on the fill-in test to a significant degree. With regard to the tasks checking the retention of vocabulary, subjects under the context treatment significantly outperformed subjects under the word list treatment on all three types of assessment tasks and they also scored higher than subjects under the semantic mapping treatment (although not to a significant degree). Pedagogical implications for EFL classroom teachers are suggested. (Contains 4 tables.)