OBJECTIVES: Bright light therapy (BLT) was reported as an effective adjunctive treatment option for bipolar disorder. Previous meta-analytic study showed that augmentation treatment with light therapy significantly decreased the severity of bipolar depression. However, most of included studies were case-control studies and several of them focused on BLT that was provided in combination with sleep deprivation therapy. METHODS: In this meta-analysis, we used several electronic databases to search the studies and included only randomized controlled trial (RCT) studies to compare BLT with control experimental groups for treating bipolar depression with pharmacological treatment to clarify the adjunctive efficacy of BLT. We searched the databases of EMBASE, MEDLINE, Scopus, The Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health Literature, and Clinicaltrials.gov for studies published in English until September 19, 2019. Two researchers conducted the literature screening, data extraction, and methodological quality assessment independently. The main outcome was the response rate and remission rate. We used the Review Manager 5.3 Software for the meta-analysis. RESULTS: Four trials with a total of 190 participants (intervention: 94, control: 96) with bipolar depression were evaluated to gauge the effects of light therapy. The meta-analysis showed risk ratios of 1.78 (95% CI 1.24-2.56, p = .002; I CONCLUSIONS: Bright light therapy is an effective treatment for reducing depression symptoms among patients with bipolar depression.