This chapter includes a section where background information for understanding lexical processing research is introduced. This includes characteristics of lexical representation, research methods, and lexical processing effects. The chapter then goes on to review empirical studies that were intended to understand the structure of the L2 lexicon and the role of the first language in L2 word recognition and other L2 word recognition findings. The topics reviewed include the importance of form-based connection in the L2 lexicon, the episodic nature of the L2 lexicon, the transfer of word recognition strategies and skills, similarities in L1 and L2 word recognition, automatic activation of L1 translations in L2 word recognition, the frequency effect in L2 word recognition, and the integration of new words into the lexicon.