This paper investigated the effects of Korean syllable structure on the acquisition of English consonant clusters on the basis of the speech data collected from a total of 8 Korean middle school students (2 females and 6 males). A total of 24 English monosyllabic words that formed 8 different quasi minimal triplets was employed and recorded. Each triplet consisted of mono-consonantal, bi-consonantal, and tri-consonantal words like pin, spin, spring or pin, pink, pinks. The three words at four triplets were differentiated by the number of consonants at the onset position and those at the other four triplets, at the coda position. Using a 5 point-scale scoring method, two native English speakers rated the speech data in terms of (i) intelligibility and (ii) the scoring of bi- and tri-consonantal words with three points being fixed on mono-syllabic words. The main finding was that the tri-consonantal words scored the lowest, bi-consonantal words were in the middle, and mono-consonantal words scored the highest. But, this general tendency held true only at the words dissimilar at the coda position. At the onset position, on the other hand, the mono-consonantal words scored the lowest. The in-depth analysis that followed the rating showed that a comparison of the words in terms of the syllabic intelligibility can be properly made only when each consonant comprising a syllable is intelligibly articulated on its own.