Unlike the other dioceses of the Evangelical Lutheran Church of Finland, the diocese is not formed on a geographical basis. All the Swedish-speaking parishes and dominantly Swedish-speaking bilingual parishes of the church belong to the diocese, regardless of their location.
This diocese differs from others in the Evangelical Lutheran Church of Finland in that it is not organized according to geographic areas. Instead, all Swedish-speaking congregations, including those with a majority or minority Swedish-speaking population, are part of this diocese, regardless of where they are located.