The role of science has been widely discussed in the context of the granting of exclusive patent rights to novel technologies; for example, the morality or patentability of stem cell, human genome and biotechnology has been subject to great debate (Laurie 2004 : 59; Laurie 1996 ; Porter et al . 2006 : 653). However, the study from the view of a precautionary approach (PA) or risk management after the granting of intellectual property (IP) has seldom been carried out. This chapter therefore aims to explore the role of the PA in TRIPS with an extended discussion on compulsory licensing. It is argued that a risk factor arising from the PA has a role to play in the IP regime, and that in contemporary society it is essential and legitimate to employ the PA in compulsory licensing of pharmaceutical patents under a public health emergency.