The Global Food Safety Initiative (GFSI) has evolved into a leading private rule-maker in the field of global food safety. To showcase the evolution of GFSI, we discuss the transitions in its governance structure, its activities and its framing as perceived through the lens of legitimacy. Building and maintaining legitimacy is of vital importance to GFSI. As a transnational private rule-maker, it cannot do without cooperation with other parties. GFSI’s evolution, we argue, has unfolded via processes of pluralisation of its constituents, increased transparency, ratcheting up of food standards’ quality, and globalisation of its benchmarking activities. Despite its growth and the inclusion of other participants in its governance, GFSI has not changed its roots: it remains an industry-led organisation relying on the participation of food safety experts of large food corporations. We will show that many of the changes the organisation has gone through can be interpreted as a response to crises, defined as fundamental objections and doubts voiced by external actors against GFSI or the practice of food certification more generally.