As the European Union embarks the ten new member states a number of challenges arise. The risk persists that limited capacities of the new member states and rigid practices of the old ones may lead to strategic decisions that would lack innovative approaches. Along with under-utilisation of the available funds and instruments this might put the new member states in a situation where they are not capable in gaining sufficient speed for cohesion consequently causing unpredictable distortion of the enlarged single market. The upcoming enlargement will have an inevitable impact to various spheres of life around the Baltic Sea. Metropolises, the ones on the eastern side of the sea, in particular, are playing an increasing role in the forming regional market. Unless a co-ordinated intervention is in place the process might lead to increased development disparities among the BSR countries. The Baltic metropolises are well on the way to join the bunch of the larger urban regions like Berlin that are the drivers behind BSR’s economic development. Too often the locally focused approaches to various development issues are not coordinated on the regional level and thus fail to bring the desirable effect. The project partnership consists of three Baltic States – Latvia, Lithuania, and Estonia. The project was carried out by Riga City Council in cooperation with Vilnius City Municipality, Tallinn City Government and the Baltic International Centre for Economic Policy Studies (BICEPS). The project contributed to sustainable development of the Baltic metropolises through creating a coordinated approach to investment planning and management in the metropolitan areas. Creating an implementing investment strategies that respect the individual strengths and competitive advantages of each the metropolis within the framework of the development perspectives of the Baltic Sea Region has created a greater impact on the reduction of the East-West divide than chaotic and uncoordinated attraction of incidental investments, which fail to generate the desirable long-term effect. The project dealt both with designing the strategies, improving the investment management processes, working with the different stakeholders whose cooperative attitude were crucial to the goals of the project, as well as increasing the availability and accessibility of information to support the implementation of the developed approach. Creation of administrative instruments such as joint working groups will ensure accomplishment of investment planning and management approach through implementation of specific policy actions in specific areas resulting in durability effect.