A comparison of the demographic past of the two German states shows that, although some important similarities remained, some demographic patterns have had a diverging tendency, With respect to aging, this has resulted in a somewhat younger age structure and a slightly more favorable demographic reproduction for East Germany. The demographic aging of the German population will continue, which at the same time will challenge the pension system. Testing different possible solutions to the pension problem, including strong inmigration, showed that there is no sole demographic answer to the problem. Instead, a combination of different measures will perform best.