This article examines the forces that shaped the responses of the urban commons to the Reformation in Augsburg. Developing work by Blickle and others, it considers the extent to which traditional communal ideals were reflected in measures to construct a system of ‘sacral corporatism’. An examination of the attitudes of guildsmen towards communal values and institutions shows variation in their views, even on such basic points as the identification and imposition of the ‘common good’. Case studies show how predominantly poor weavers were attracted to the call to enforce communal principles as a means of defending their status and incomes. To this end they welcomed evangelical teaching, for it provided scriptural and ethical endorsements of corporate action. In contrast, members of the butchers' guild, who were involved in a capital intensive occupation, resisted communal restraints on their freedom to trade and make profits. The butchers' opposition to the Reformation rested more on their rejection of ‘sacral corporatism’, as advocated by reformers in Augsburg, than on support for Catholicism. Augsburg shows the significance of communal values in the urban Reformation, but it demonstrates that these were neither static nor uniformly accepted. On the contrary they were themselves the subject of dispute.