This article takes a meta-analytic approach to investigate the efficacy of written corrective feedback in second language (L2) writing instruction. With its widespread practice in second language acquisition (SLA), written corrective feedback has increasingly garnered attention as much as it has continued to be a subject of considerable controversy. Aggregating findings from 35 primary studies, the study synthesizes and reviews current empirical research in the field. It seeks to complement previous meta-analyses by incorporating more recent studies and varying the inclusion criteria. Through the examination of ten moderator variables, it also aims to shed light on some factors that might mitigate the efficacy of written corrective feedback. Findings reveal a moderate overall effect, indicating that written corrective feedback has the potential to improve L2 written grammatical accuracy. In addition, direct feedback demonstrated a larger effect size than indirect feedback, though differences were not statistically significant. The study also identified learners' proficiency to be the strongest mitigator. Implications regarding how some of the key findings can be utilized to maximize the impact of written corrective feedback in L2 writing instruction are discussed.