Reconstructive surgery for critical leg ischaemia (CLI) increased in both hospital- and population-based patient samples over 12 years. In the referral centre amputation numbers were unchanged over this period, although amputation carried out for patients with CLI decreased from 58 to 35 per cent. In the population sample amputation numbers decreased by 25 per cent and amputations of patients with CLI decreased from 79 to 43 per cent. Patient characteristics and amputation patterns were different in the two settings. Amputation rates as a measure of the efficacy of an arterial reconstruction policy should be used only on a population basis. The analysis is skewed by selection bias in referral centres.