OBJECTIVES: To examine the geographic variation trends in the annual prevalence of critical limb ischemia (CLI) in the US elderly population. METHODS: Using national medical claims data from 2006 through 2008, all patients who were aged 65 years or older and diagnosed with CLI were identified. The direct standardization method was used to assess year, age, gender, race and diabetes-adjusted prevalence of CLI. The change in prevalence of CLI over the 3 years was assessed and the variation in the prevalence of CLI was tested by state. RESULTS: Geographic variation in the prevalence of CLI was obtained for patients over the age of 65 when adjusted by age, gender, race and diabetes status. Although approximately constant prevalence of CLI was reported in Utah (less than 0.15%) and Maryland (greater than 0.30%), a progressively increasing prevalence of CLI was observed in Montana (2006: 0.149%; 2007: 0.163.%; 2008: 0.277%) and Delaware (2006: 0.245%; 2007:0.247%; 2008: 0.330%) while progressively decreasing prevalence of CLI was observed in Arkansas, Colorado, Georgia, Ohio, Virginia, West Virginia, and Washington. The total trend over 3 years followed the pattern of higher rates in eastern states and lower rates in western states. CONCLUSIONS: The spatial distribution of CLI prevalence is uneven and strongly suggests a geographic variation of CLI risk areas. Targeted prevention and treatment could help gain better control of CLI in the United States.