Introduction: Galectins (Gal) were linked with inflammatory responses in the central nervous system, may play an important role in the pathogenesis of BD.In this study,we aimed to investigate whether serum Gal-1 and Gal-3 levels are related to BD., Methods: 36 patients diagnosed with BD were included.C-Reactive Protein(CRP),Gal-1,Gal-3 blood levels were evaluated on the first day of hospitalization and the third week of treatment and compared with 41 healthy controls.The severity of the illness was evaluated with the Young Mania Rating Scale (YMRS)., Results: CRP levels of BD patients at hospitalization were significantly higher than the third week of treatment and healthy controls.Gal-1 levels on the first day of hospitalization and the third week of treatment were found higher than the healthy controls.There was no significant difference in Gal-3 levels of the patients on the day of hospitalization compared to healthy controls;at the end of the 3rd week of treatment,Gal-3 was statistically significantly higher than the first day of hospitalization., Conclusion: Our study is valuable in that it is the first study to show the change in Gal levels after treatment and to evaluate the role of Gal in BD.Gal-1 may play roles in the pathophysiology of BD.Gal-3 may be a biomarker candidate for the evaluation of the treatment response., Competing Interests: The authors report no conflicts of interest.