A web site for disease prevention and health promotion was created within the framework of the "National Health Program", a health promotion project (HPP). The article describes the functional options of the site and its effect evaluated after one year of operation. The site has three main functions: an information tree, a risk calculator, and an option for making an appointment for a complimentary preventivě clinical checkup. The risk calculator enables direct evaluation of individual lifestyle risk factors, such as nutrition, alcohol consumption, physical activity, and smoking, together with some clinical parameters. The applied methodology of evaluation of nutrition and other lifestyle factors is originál and fully described in the article. Over the course of the one year evaluation period, more than 29 000 user entries were recorded. In a basic questionnaire, 97 % from 2002 respondents favourably answered the question: "Does this server provide information you consider important for your health and good condition?" In total, 1 186 visitors completed the risk calculator. Their average age was 34 years (range 13-61), 63 % were female. Three months after registration, all registered users obtained a questionnaire for the web site evaluation. The response rate was 89 %, 100 % respondents claimed a change in their knowledge, 88 % a change of attitude, and 75 % a change of behaviour. A preventivě clinical check-up made via the site was provided to 435 individuals, 42 % (167 individuals) underwent a repeat check-up. In all repeated check-ups a certain improvement, but no deterioration, was recorded. The web pages described are still freely accessible, mainly for non-professional, but also professional usage for the practical prevention of non-infectious diseases.

        Key words: web pages, disease prevention, healthy lifestyle, evaluation of individual risk factors, nutrition, physical activity