The aim of this study was to estimate costs of treating venous leg ulcers in Sweden and the United Kingdom during 1 year and to quantify costs in different health states. The costs of treating four different types of venous leg ulcers were estimated for 52 weeks by a stochastic health economic model, which simulated resource use data obtained from prospectively collected patient data, expert panels in the two countries, and published scientific literature. The average cost of treating an ulcer varied between 1332 Euro and 2585 Euro in Sweden and from 814 Euro to 1994 Euro in the United Kingdom. Cost of treating large ulcers (>/= 10 cm(2)) of long duration (>/= 6 months) was highest in both countries. Frequency of dressing changes and duration of time for each dressing change were higher in Sweden than in the United Kingdom, resulting in higher total cost per patient in Sweden. An important factor for the total costs was time to heal. Other important variables influencing treatment costs were frequency and duration of dressing changes. Actions to reduce time used for dressing changes and the total time to healing are thus very important in reducing costs spent on treatment of venous leg ulcers in both countries.