For centuries, Gregorian chant has served as a monophonic song written for the religious services of the Roman Catholic Church, but Korean Catholics first encountered this chant in the early nineteenth century. Korean Catholics ultimately became more attracted to the Korean translations of these chants, as opposed to the original Latin versions. This article introduces some issues related to the language translation of Gregorian chant, especially for chants performed in Holy Week. The issues include discrepancies in the number of syllables, shifts in melismatic emphasis, difficult diction in vocalization, briefer singing parts because of space limitations, challenging melodic lines, and translation losses from neumes to modern notes.