Technology-mediated vocabulary development (TMVD) in a second language (L2) covers a wide range of instructional and learning treatments, contexts, and technologies and is situated in a broader field of second language vocabulary learning. Vocabulary knowledge is a complex, multidimensional construct that has been interpreted and categorized in second language research in many different ways. This review identifies methodological practices in research into L2 TMVD and provides a synthesis of learning and instructional approaches, aspects of vocabulary knowledge being investigated, and measures of vocabulary development used in this research. A sample of 82 primary studies from 2010 to 2017 was selected and coded for target methodological features. The results of the review show that TMVD research has achieved a certain degree of methodological maturity, while a number of issues have also been identified. These issues include: the practice of comparing technology-mediated instruction with "traditional" instruction without technology, insufficient reporting of participants' L2 proficiency, and a dearth of treatments targeting fluency development. The review also showed a preference for evaluating the knowledge of individual vocabulary items rather than the development of the L2 lexicon, and insufficient use of online and implicit measures of vocabulary knowledge. Recommendations for future TMVD research are provided.