This study analyzed Vietnamese speakers’ production of Korean consonants and the pronunciation errors that occurred. For this study, I collected natural utterances from 26 Vietnamese marriage immigrant women in Korea. The results of this study indicate that Vietnamese speakers have difficulty distinguishing lax from tense consonants at word-initial onset position and aspirated consonants from others at word-medial onset position. At coda position, the most frequent occurrence was that the lateral /l/ was replaced with the nasal /n/. This is mainly due to the difference between phonemic systems of the speaker’s native tongue and Korean. Because there is no discrimination between lax and tense consonants, and the lateral /l/ is not allowed at coda position in the phonemic system of Vietnamese. However, phonemic correspondence between first language and second language can not account for all the observed errors. For example, /n, m, ŋ/ at coda positions were often confused in place of articulation even though the phonemic system of their native tongue has the consonants corresponding to each nasal.