Declining union density in Australia and Britain has focused attention on the need for union reorganization. This article examines how the development of closed shops in the two countries influenced member exit rates and the internal union relations now affecting union renewal. Findings show that legislative support for the Australian closed shop tended to foster more union dependency on state and employers, union bureaucratization, less active stewards and more dissatisfied members than in Britain. The subsequent outlawing of the Australian closed shop and increasing employer hostility resulted in higher levels of density decline than in Britain. While the greater resilience of British density supports the case for developing strong workplace unionism, the relative bureaucratization of Australian unions within an increasingly antagonistic context, against the British situation of relatively indifferent employers and steward independence, limits the transferability of strategies designed to achieve union renewal.