Background/aim: To investigate serum ischemia-modified albumin (IMA), oxidized low-density lipoprotein (ox-LDL) levels, and paraoxonase 1 (PON1) activity in patients with diabetic foot. Materials and methods: Thirty patients with diabetes mellitus (DM), 30 patients with diabetic foot (29 and 27 of these patients had type 2 DM, respectively), and 30 healthy volunteers as the control group were included in the study. The patients with diabetic foot were divided into 2 groups, as those who had or had not undergone lower extremity amputation. Serum PON1 activity, ox-LDL, and IMA levels were measured. Results: Serum PON1 activity was lower (P < 0.05) and ox-LDL levels were higher (P < 0.05) in the diabetic foot group than in the control and diabetes groups. Albumin-adjusted IMA values were higher (P < 0.001) in the diabetic foot group compared to the diabetes group. The postamputation levels of IMA were decreased compared to the preamputation condition (P < 0.05). Conclusion: The low activity of PON1 and the high levels of ox-LDL and IMA may play an important role in the pathogenesis of diabetic foot. The use of these parameters in the follow-up of patients with DM may prevent the development of diabetic foot. In order to reach a definitive judgment, further studies with a larger number of subjects are necessary.