The restructuring of Irish telecommunications brought major changes to employment in the sector, including increased use of contingent labour. The Communications Workers Union won bargaining recognition in the main subcontract supply firm.The recruitment of contingent workers brought new challenges in terms of reconciling the interests of members working on traditional employment contracts and those with a variety of contingent employment forms. Successful organizing campaigns also raised the questions: why do contingent workers join the union and what does union membership mean to them? These developments are set in the context of union responses to sectoral restructuring in other countries, and possible lessons are drawn for broader attempts by unions to recruit and represent contingent workers.