During the last 10 years or so, a number of corporate social responsibility (CSR) initiatives have been introduced in global supply chains, which aim to improve the conditions of workers engaged in producing goods for export. This article discusses the observations of CSR in practice in the Costa Rican-United Kingdom (UK) banana chain. The banana chain makes for an interesting case study because there are dominant corporate actors at each end who are in a position to influence the conditions experienced (...) by workers on banana plantations. At the top of the chain there are four major UK supermarket groups who control access to the retail market and as selfappointed guardians of consumer interest are demanding that producers adopt more socially responsible practices. At the other end, banana production is highly integrated and controlled by three large North American agri-businesses who have developed their own social and environmental certification programmes. Costa Rica also makes for an interesting country to locate the study as it has a tradition of state-led policies to protect worker rights. Yet, in spite of CSR commitments made by both supermarkets and producers that emphasise health and safety and the country's established Labour Law, this article shows that there are problems for workers when they are forced to meet demanding production schedules. Furthermore, it suggests that whilst supermarkets continue to drive down consumer prices and put pressure on producers to reduce costs, a downward spiral of working conditions is created regardless of the CSR policies in place. However, this article also identifies that changes to supermarket behaviour is possible when consumer trust is at stake. (shrink)