This paper investigates Korean EFL learners’ perceived phonetic dissimilarity of English liquids /l/ and /r/ to test the Korean learners’ relative acquisition difficulty of the two English liquids. Contrary to the prediction of the contrastive analysis hypothesis, a hypothesis from Flege’s (1995) Speech Learning Model asserts that the greater the perceived phonetic dissimilarity between an L2 speech sound and the closest L1 sound, the more likely learners will be to discern the difference between the L1 and L2 sounds. Fifteen Korean EFL learners were asked to judge how well English /l/ and /r/ in various phonological environments represent the Korean liquid, using a scale ranging from 0 (“not like”) to 6 (“exactly the same”). The results of the judgment task showed that Korean L2 learners perceived English /l/ to be more similar to Korean /l/ than English /r/ in syllable-initial, consonant cluster, and intervocalic positions, but not in syllable-final position. The results of the present study are expected to provide a basis for future research which investigates Korean learners’ perception and production of English /l/ and /r/.