The development of a trade union movement in Hong Kong, as in other industrial societies, has been an uneven process. We focus in this paper on three major growth waves - 1920-26, 1946-51 and from the early 1970s to the 1990s - when union formation and membership have risen substantially. We describe the strategies of organisational development pursued by Hong Kong trade unions during these three growth waves, the economic, political and social circumstances in which these choices were made, and the consequences of these choices for the movement’s subsequent development. We argue that environmental variables including the nature of market economy, the voluntarist approach to labour relations of the colonial political regime, and the character of the working population have interacted with strategies of organisational development to affect the ease or difficulty of creating and sustaining union organisation. We conclude with a brief discussion of the impact on the union movement of China’s resumption of sovereignty over Hong Kong and of the recent economic turmoil in the region.