There is a growing consensus that the ability to understand and process visual information should be part of the second language (L2) listening construct; however, the findings of studies exploring the use of visuals in L2 listening assessment contexts remain inconclusive. To better understand the underlying reasons for these inconclusive results, this article employs a methodological synthesis to examine different methodological aspects of primary studies. The synthesis starts with an overview of its methodology that describes the selection and search criteria, data coding, and analysis of data from 45 studies comprising journal articles, doctoral dissertations, book chapters, and conference proceedings published in the past 50 years. Driven by five research questions, the synthesis examines methodological aspects of primary studies, including research aims, research designs, data collection and analysis methods, study and participant characteristics, design characteristics of L2 listening assessment instruments, and test administration procedures. The results reveal a panoply of differences among research methodologies used in primary studies. In discussing the results of this methodological synthesis, this article highlights the patterns in reviewed methodologies, identifies key methodological issues in primary studies, and concludes with recommendations for expanding and advancing this line of research.