Background: The objective of this study was to evaluate whether admission neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) might reflect amputation in patients with critical limb ischemia (CLI) who could not get surgical or radiological (percutaneous transluminal angioplasty) revascularization. Methods: A total of 104 patients with nonreconstructable CLI over a 5-year period were collected prospectively. Results: Admission NLR levels of ≥3.2 and a PLR of ≥160 were found to represent the optimal cutoff values to risk stratification of patients. If both levels were elevated, patients had a median overall limb survival of 22 months. For cases where both levels were less than the cutoff values, the median overall limb survival time was not reached but was greater than 60 months. Conclusions: Admission NLR and PLR both merit further evaluation as prognostic indices in patients with CLI.