Lobbying has become an inseparable companion of the decision-making process and fi rms but also other social actors (non-governmental organizations, individuals, private and civil sector) are forced to reflect this fact, if they want to promote their interests eff ectively and if they want to avoid regulation that would harm their interests. The real modern lobbying in the EU is associated with the 80s of the 20th century.This is mainly due to the importance of the Single European Act, which involved the European Parliament in the decision-making process, accelerated completion of the single market and restored the qualifi ed majority voting in the EU Council. This led to the strengthening of the supranational elements in the European Union. The power and infl uence of the supranational institutions was enhanced and the supranational methods of decision were restored (qualifi ed majority, later veto of the European Parliament). The interests groups were also not any more limited by the national arena. The Single European Act and the following primary European treaties opened a new space for the interest groups and introduced newopportunities and possibilities for their actions. The increase in lobbying activities in Brussels therefore dates back to the second half of the 80s. The quantity of lobbying and its study further expands proportionally with closer European integration, along with higher level of transferring powers to Brussels. Currently Brussels is the second largest lobbying centre in the world, after Washington.