Increased oxidative stress (OS) in chronic kidney disease (CKD), and particularly in those undergoing hemodialysis (HD), is widely recognized. We aimed to evaluate ischemia modified albumin (IMA) as a marker of OS in CKD patients who are not yet on HD compared to chronic HD patients. A cross-sectional study was conducted in Hitit University, Corum, Turkey in 2015. In this study, 39 chronic HD and 36 CKD patients in stage 3–4 were included, as well as 34 healthy individuals as a control group. IMA levels in HD patients (before and after HD session), stage 3-4 CKD patients and control group were evaluated using the ELISA method. Pre-HD and post-HD albumin levels were measured and albumin-adjusted IMA (aIMA) levels were calculated. IMA and aIMA levels were higher in chronic HD and CKD patients who are not yet on HD, compared to healthy individuals (IMA, 179.76 ± 60.46, 209.67 ± 69.84, 67.41 ± 32.22, P