Augmented reality (AR) is an immersive, interactive, and engaging advanced information technology and it is widely used in language learning. Although several studies have evaluated the effectiveness of AR in EFL learners' language gains, these research findings are inconsistent. Therefore, this study conducted a meta-analysis to analyze to what extent AR intervention in the EFL context could affect EFL learners' language gains and what variables may moderate its impact. The results showed that AR facilitated EFL learners' language gains at a moderate level (g = 0.63). The moderator analysis indicated that participants' educational level, instructional strategies, and target language learning skills significantly moderated AR's impact on EFL learners' language gains. This study provided systematic and empirical evidence for a strong causal inference of AR learning on EFL learners' language gains.