Often described as a culturally homogenous ethno-religious community, the Transylvanian Saxons, one of the main German-speaking groups in post-1918 Romania, have experienced various forms of internal diversification during the second half of the last century. In some local parishes, Transylvanian Saxons shifted their denominational affiliation from Lutheranism to neo-Protestantism, becoming Baptists, Adventists, or members of The Brethren, also called Christians According to the Gospel (Evangeliumschristen). The latter organization, with roots in the 19th-century movement The Plymouth Brethren, included members from all large Romanian ethnic groups, with an overall majority of Romanians, followed by Germans and Hungarians. The case study presented in the paper focuses on two local congregations of Transylvanian-Saxon Brethren, the initial moments of their formation, and the relationship between members of these congregations and the majority Lutheran population, in an attempt to identify structures and processes of minoritization and social hierarchization.