In China extensive, co-ordinated strikes such as those that have taken place in Cambodia in recent years remain rare, with most protests initiated by Chinese workers contained inside single factories or industrial zones. Also, while Cambodian workers often mobilise for their interests and broader policy issues, such as the determination of the minimum wage, Chinese workers largely limit themselves to protests against violations of their legal rights. How can these different patterns of labour activism be explained? Through factory gate surveys and interviews conducted during the summer of 2016 in a sample of Hong Kong-owned garment factories in Dongguan and Phnom Penh, this study provides a comparative analysis of the root causes of labour activism in China and Cambodia. In particular, the article focuses on three elements that play an important role in determining labour activism: the expectations of the workers regarding wages; the workers' perception of the labour law and the legal system; and trade union pluralism.