As part of a uniting Europe, border areas experience a significant change. Working and living, shopping and leisure are not tied to national borders anymore. Due to these changes, planning in border regions faces new challenges. On the one hand, borders are less and less barriers to spatial patterns of interrelations, but on the other hand, cross-border planning processes are often limited by heterogeneous planning systems. In order to ensure an adequate spatial development, planning must be adapted to this changing image. Cross-border interaction processes attempt to meet the new requirements. Cross-border interactions in spatial planning are a much-discussed field; in particular the possibilities and limits of cross-border spatial development are important areas of research. In the course of this thesis, the organization of cross-border interaction processes in the field of planning in the Austrian-Hungarian border area is analyzed. The work deals with the difficulties, conflicts and potential for cross-border interactions, with special focus on the bilateral interaction processes of the past 10 years. The objective of this thesis is to identify the potential of cross-border interaction in the Austro-Hungarian border area under the existing conditions. The border between Austria and Hungary is subject to constant change; in particular the meaning attached to the border has continually changed in the last hundred years. A new border divided the region of West Hungary after World War I, while after World War II the development of the border area was characterized by the Iron Curtain. Due to the integration process of the European Union, there is again a reassessment of the border regions. The methodical approach includes both literature analysis and expert interviews. Information obtained through the analysis of development of cross-border interactions was combined with individual experiences and opinions of Austrian and Hungarian planning experts. Based on the analysis of the intensity of interactions in the Austro-Hungarian border area, the thesis highlights that the border is still an essential interface for planning and spatial development - in spite of permeability in the context of the European integration process. The final recommendations are aimed at the future organization of the cross-border interaction processes to develop an efficient transnational spatial development in the study region.