Objective: To investigate the potential role of thiol/disulphide homeostasis as a novel biomarker of oxidative stress in pa tients with diabetes and undergoing hemodialysis (HD) and its correlation with other oxidative stress markers. Materials and Methods: This study included 82 patients with end-stage renal disease undergoing HD for four hours, threetimes weekly for more than 24 months in the dialysis center. Of the 82 patients, 47 were non-diabetic and 35 were diabet ic. Blood samples were collected from the patients before and after the HD sessions. The thiol/disulfide pair tests wereperformed and total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), ischemia-modifiedalbumin (IMA) levels, albumin levels, ceruloplasmin, catalase activity (CAT), and myeloperoxidase (MPO) activity were de termined in the serum.Results: The TAS values in all the patients, both diabetic and non-diabetic, decreased significantly after HD (p<0.001,p=0.003, and p<0.001; respectively). The TOS, albumin, native thiol (p=0.001, p=0.007, p=0.001, respectively), OSI, CAT,ceruloplasmin, IMA, MPO, and total thiol (p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively) valuesincreased significantly in all the patients after the HD session. The TOS, OSI, CAT, IMA, albumin, MPO, native thiol, and per centages of native/total thiol, ceruloplasmin, and total thiol values (p=0.002, p=0.002, p=0.002, p=0.001, p=0.008, p=0.001,p=0.001, p=0.003, p=0.023, and p<0.001; respectively) increased significantly in patients with diabetes after the HD session.Conclusion: In this study, we demonstrated the relationship between oxidative stress markers, which play a significant rolein the pathogenesis of diabetes, and thiol/disulfide balance undergoing HD patients.