Backgrounds: Bipolar depression is still a very difficult to treat condition with low success rates of antidepressant drugs, high rates of morbidity and suicide risk and antidepressant-emergent mania risk. Despite a growing body of evidence has been generated over the last decade about Light Therapy (LT) as an effective treatment for depression the management of it continues to be a point of debate for Bipolar Disorder especially when considering non-seasonal pattern. Methods: We systematically screened current literature using the PubMed electronic platform. We considered "mood disorder", "depression" and "light therapy" as keywords for the search. Results: We retrieved 1907 papers. After the screening, we selected 11 papers to be included in the analysis, treating 195 patients affected by bipolar depression. 5 studies were RCT studies. The overall analysis, including non-RCTs, showed a positive effect of the treatment in all the included studies (ESs: -1.46, 95% CI:-1.677 to -1.242; p<0.001). A significant effect of LT compared to placebo was found also in RCTs (ESs: -0.501, 95% CI: - 0.777 to -0.225; p<0.001). Limitations: A high heterogeneity between the studies was found when including non-RCTs and the number of RCTs was small CONCLUSION: We confirmed the -efficacy of LT as antidepressant non-pharmacological therapy also in bipolar depression.