This thesis investigates the difficult interaction between trade marks and domain names and demonstrates, in light of European and U.S. court decisions, that the current trade mark law has its limits to address domain name disputes. The author analyses the current trade mark law in the U.S. and Europe and identifies the approaches courts have taken to resolve trade mark issues arising in cyberspace. He looks at the international administrative dispute resolution system and discusses potential technical solutions to the current difficulties. The result of this analysis shows that the inherent tension between trade marks and domain names demands a careful application of trade mark law. Especially in cases where both, the trade mark holder and the registered domain holder seem to have a legitimate interest in the domain name, the strict application of trade mark law without considering the peculiarities of the medium Internet does not always lead to fair results.