This study uses research synthesis and quantitative meta-analysis approaches to investigate the effects that reading has on second language vocabulary learning. It discusses the procedures of conducting a meta-analysis in the field of applied linguistics. Then the study systematically reports on findings from forty-four unique sample studies that met the inclusion criteria. In addition to the investigation of the link between reading and second language vocabulary learning, the study discusses methodological issues that have made it difficult for second language vocabulary researchers to understand better the role that reading plays in second language vocabulary learning. In the end, the study presents further research avenues for research synthesis and meta-analysis approaches, and the conceptualization of research investigating the effects of reading on second language vocabulary learning.