Historic developments that occurred in the last centuries have affected the barrier effect of national borders in Europe and, consequently, the degree and the in- tensity of the cooperation between neighbouring countries. However, the establishment of the European Single Market, in the last three decades, has deepened the cross-border cooperation inside the EU Territory. In this respect, the INTERREG-A initiative has played a major role, since 1990. This article intends to shed some light on the progress of the cross-border cooperation in the Swedish-Norwegian border region, and the territorial effects of the INTERREG-A programme in the reduction of the barrier effect along the border in five dimensions (institutional-urban, accessibility, culture-social, environmental--heritage and economy-technology).