The church serves mainly the area of Lower Saxony, especially in East Friesland, the county of Bentheim, and the regions of Gottingen, Osnabruck and Bremerhaven. In addition, it has a number of isolated congregations. Most of its congregations originated in Reformation times. Through the work of John a Lasco (at Emden 1540-49), these congregations were led to adopt the Reformed faith. Reformed congregations in the county of Bentheim (since 1588) were influenced by Strasburg, in the county of Lingen, by the Netherlands House of Orange at the end of the 17th century. In 1882, 114 of these congregations united to form the church. Other congregations subsequently attached themselves to it, for example those of Huguenot origin. In 1925 the church adopted its present form of government.

The church is governed on presbyterian lines. The supreme court is the synod. The Evangelical Reformed Church in North-West Germany is one of the smaller members of the EKD. On the basis of the Concord of Leuenberg the church is in eucharistic communion with all EKD member churches. It maintains particular relations with partner churches in Sumatra/Indonesia, Togo, Ghana and South Africa, especially with the “Belijdende Kring” in that country, and with churches in Hungary, Romania and former Yugoslavia.