Union renewal has been the subject of debate over the last two decades. Via a review of these debates, a revision of the union renewal thesis is presented, suggesting that union renewal should be examined as a process of transition. Three analytic dimensions of renewal are identified and presented, each arising out of a consideration of the debates: union organisation, union capacity and union purpose. The proposition is that an understanding of contemporary unionism involves a consideration of the ways renewal involves a multi-faceted transition in relation to the political economy of trade unionism. The way to understand this characterisation is to reconsider theories about unions in terms of a dialectic, addressing the inter-relationships and integration of union organisation, capacities and purpose.