This study synthesized the research on listening instruction (LI) and its effectiveness on L2 learners' listening competence development based on studies published from 1980 to 2019. After a literature search, well-designed studies that involved not only experimental or quasi-experimental and control groups but also pretests and posttests were selected for the analysis. A total of 39 samples from 32 primary studies with 2,797 participants were included. A random-effect model was employed to assess the differences in the treatment effect, which might be moderated by mediator variables: treatment length, treatment method, implementation types, and measurement types. The result showed a small effect size (Cohen's d = 0.25) for listening instruction. Meta-regression for treatment length showed that the longer the treatment period is, the better the effectiveness is. A significant difference was found for implementation types, but not so for the treatment methods and measurement types. Pedagogical implications for LI are discussed, and directions for future studies are provided.