Background: Sarcopenia (SP) is a syndrome described as generalized and progressive loss of muscle mass and strength that may cause fall, fractures, disability and death. Oxidative stress might be a probable etiologic factor in SP as well. SP is a comorbid syndrome that is seen in chronic illnesses. If these two considerations are taken together, one may also think that SP could be also seen in bipolar disorder (BD), because it is a chronic disorder and oxidative stress was related to both illnesses. In our study, we proposed to investigate the prevalence of SP in BD patients.