The purpose of this study is to examine cohesive devices in English writing textbooks and Korean college students’ writings through text and corpus analyses. An analysis of three writing textbooks used in one college English program in Seoul showed that the textbooks did not cover a full range of cohesive devices; instead, they focused on sentence transitions and conjunctions, which L2 writers often overuse or misuse. Other cohesive devices such as demonstratives and lexical cohesive devices such as synonyms, paraphrasing, or collocations, however, were rarely covered. To understand how Korean college students actually use cohesive devices in writing, this study also analyzed the frequencies of sentence transitions and demonstratives in learner and native speaker corpora. The results revealed L2 learners’ tendency to overuse sentence transitions and demonstrative pronouns compared to native speakers. However, the results also showed that as proficiency increases, learners tend to use fewer sentence transitions.