It has grown due to immigration from Eastern Europe, especially Romania, Greece, the former Soviet Union, and the former Yugoslavia.
According to the 2011 census, 2% of the population identified as Orthodox, although this encompasses a number of different churches.
Likewise, The Orthodox churches are involved in most regional and local working group of the ACK.
There are also bilateral relation with the German Bishops' Conference and the Evangelical Church in Germany (EKD) with discussions on theological issues.
For example, several documents were adopted in 2006 to dogmatic questions in a joint working group of the Greek Orthodox Metropolis of Germany and the German Bishops' Conference.