Background Some diabetic feet heal without complication, but others undergo amputation due to progressive wounds. This study investigates the risk factors for amputation of diabetic feet. Methods A total of 55 patients who visited our institution from 2008 to 2012 were included in the study. The patients with abnormal fasting blood sugar levels, lower leg vascularity, and poor nutrition were excluded from the study group, and the wound states were unified. The patients were categorized into a treatment success group (n=47) and a treatment failure group (n=8), and their hemoglobin A1C (HgA1C), C-reactive protein (CRP), white blood cell count (WBC), and serum creatinine levels were analyzed. Results The initial CRP, WBC, and serum creatinine levels in the treatment failure group were significantly higher than that of the treatment success group, and the initial HgA1C level was significantly higher in the treatment success group. The CRP and WBC levels of both groups changed significantly as time passed, but their serum creatinine levels did not. Conclusions The initial CRP, WBC, and serum creatinine levels were considered to be risk factors for amputation. Among them, the serum creatinine level was found to be the most important predictive risk factor. Because serum creatinine represents the renal function, thorough care is needed for the feet of diabetic patients with renal impairment.