Objectives: Constraint-Induced Language Therapy (CILT) is an aphasia treatment program which comprises forced use of verbal language and massed practice. There are many studies about the efficacy of CILT on aphasia, but the results are controversial. Thus, the purpose of the present meta-analysis study was to systematically evaluate the effects of CILT for aphasia and to establish the evidence-based practice of CILT. Methods: Data collection was performed from 5 databases (DBPIA, EBSCOhost, ProQuest, PubMed, RISS) which were about CILT for aphasia. Nine studies which met the inclusive criteria were entered into the meta-analysis. Effect sizes for each study outcome (standardized language test outcome) were calculated. Results: There were two main findings from the current study. First, the meta-analysis results indicated that CILT is an effective treatment method for improving both overall language ability and each sub-language area. Second, CILT was effective for both chronic aphasia and acute aphasia-overall and in each sub-language area. Conclusion: The present study suggests the comprehensive effectiveness of CILT for aphasia in each sub-language area including auditory comprehension, repetition, and naming, and its treatment effectiveness for both chronic aphasia and acute aphasia regardless of post onset time. This research unifies the complicated results of previous studies and lays the foundation for clinical implications.