In this study we made an investigation on the transformation of economic structure of two border city regions, Saarbrücken and Copenhagen. The motivation for a comparative analysis is that they have similar industrial background. Both city regions were dynamic in the first half of the 20th century however in the second half they slowed down and gradually lost some of their industrial base. This decline of industry also brought some transformation of the economic structure. To some extent they followed similar trends such as decline of industry and rise of service sector. However there are differences as well, like the diversification of economy, dependence on industry, potential for attracting the creative class and so on. Another reason for comparison is that they are both border regions and have a potential to integrate with the other side of the border. Saarbrücken has increased its interaction with the French region Lorraine and the opening of the High Speed Railway East to Paris is likely to contribute to this interaction and may lead to integration. Copenhagen, too, has been increasing its interaction with Malmo and Lund on the Swedish side. Especially after the opening of the Öresund Bridge in 2000 this interaction even got accelerated and seems to evolve towards integration. We have discussed this cross-border interaction and tried to identify to what extend these regions integrated with the other side of the border. Furthermore we tried to reveal the similarities and the differences in this integration processes in both border regions. As theoretical approach we have chosen Kondratieff Wave Theory, Porter’s Cluster Theory and Florida’s Creative Class Theory as these theories seem to explain the developments in the two regions quite well. The Wave theory makes up the theoretical framework as it reflects a global shift in the western economies especially in the old industrial zones. The two other theories points out to more specific developments in two regions such as emergence of high tech sectors as a result of creative class. Our overall conclusion is that the two regions have similarities in their transformation but also differences. Every region has its own transformation story as some local elements are involved in the process. It is not possible to have identical developments; however regions can induce similar development with the more dynamic regions in case they create similar conditions for new sectors. And it is increasingly easier to do so as the globalisation makes the production factors more mobile.