Soonhyun Hong. 2001. Output-oriented Sonorants in Korean. Studies in Modern Grammar 24, 25-46. Korean input /l/ is realized differently on the output: either [l], [r], or [n]. Input /n/ is realized differently on the surface, being crucially affected by a neighboring /l/. In this paper, we are going to show that the surface realizations of the input coronal sonorants /l/ and /n/ crucially depend on syllable structure, the Feature Geometry, and geminate structure. We will demonstrate that surface realizations of input /l/ may be correctly predicted even without triggering the controversial issue of whether or not the coda position in Korean is weighted. In addition, we observe that regressive lateral assimilation is consistently blocked across a word edge, though bi-directional lateral assimilation is observed elsewhere. We try to explain these phenomena in the framework of Optimality Theory.