Abstract: In a world full of uncertainty and constant economic changes, key issues for companies are to minimize risk of activities and to secure a long-term growth. In countries like Poland, where the two-tier board model is common with regulations in the law, supervisory boards are playing a main role in controlling management boards’ operational activities regarding implementation of previously accepted strategic goals in tight relation with a risk management. In this case, supervisory boards must act in the most effective way. Taking into consideration that public listed companies are obliged to publish all important information and in consequence they are the most transparent on the market, my decision to focus on companies listed on Warsaw Stock Exchange is the solution to the problem of presenting a real and full picture. I describe factors which determine effectiveness as well as a role of supervisory boards of Polish companies.