Idiomatic expressions play an important role in communication. They are widely used in both spoken and written discourse and are often one of the indicators of native-like proficiency. This paper discusses Chinese idioms chengyu in foreign language education, presents some observations regarding the scope of idioms predicted for the advanced level of Chinese, and introduces conceptual gaps between L1 and L2 as possible reasons for learners’ mistaken usages. This study argues that equipping students with skills and knowledge needed for reaching contextually appropriate use of idioms should be the main goal in the teaching/learning process and provides a set of practical suggestions as to which aspects of teaching idioms should be considered thoroughly.