OBJECTIVES: Limited information is available concerning the post-treatment neutrophil-lymphocyte ratio in critical limb ischemia patients who receive conservative therapy. Accordingly, this study was designed to evaluate the predictive value of the post-treatment neutrophil-lymphocyte ratio in critical limb ischemia patients without surgery. METHOD: From January 2009 to January 2011, critical limb ischemia patients were admitted to a vascular center. The demographic data, patient histories, comorbidities and risk factors were documented, and the differential cell count was determined at admission and seven days later after conservative therapy. The cutoff value of the post-treatment neutrophil-lymphocyte ratio was determined by an ROC curve. Patients were divided into groups A and B according to the cutoff value. Amputation-free survival was compared between groups. Univariate and multivariate analyses were used to identify independent risk factors. RESULT: A total of 172 patients were identified with a mean age 71.98±10.09 years; among them, 122 were male. A value of 3.8 was identified as the cutoff value of the post-treatment neutrophil-lymphocyte ratio. Groups A (post-treatment neutrophil-lymphocyte ratio ≥3.8) and B (post-treatment neutrophil-lymphocyte ratio <3.8) showed a significant difference in amputation-free survival (P<0.001). The 1-year, 2-year and 3-year amputation-free survival rates were 79.6%, 55.6% and 46.3%, respectively, in group A; however, in group B, these values were 89.7%, 79.3% and 75.9%, respectively. The post-treatment neutrophil-lymphocyte ratio was identified as an independent predictive factor for amputation in critical limb ischemia patients (P<0.001). CONCLUSION: The post-treatment neutrophil-lymphocyte ratio is an independent predictive factor for amputation in critical limb ischemia patients. Patients with a post-treatment neutrophil-lymphocyte ratio ≥3.8 are likely to suffer from amputation; amputation-free survival usually occurs in patients with a post-treatment neutrophil-lymphocyte ratio <3.8.