The precautionary principle was developed in environmental politics as a guiding mechanism for governments where new technologies, products, and processes produced potential health or environmental problems but where scientific evidence could not explain why. Anecdotal evidence of fracking suggests that it might cause water pollution or subsidence, but the scientific evidence to support this proposition is not yet in place. This paper examines the actions of the UK and Dutch governments toward fracking. Although both governments have adopted the precautionary principle into national law, neither has directly invoked it in the field of fracking, relying instead on more conventional scientific understandings of risk. In line with other papers in Science and Public Policy, this article provides a comparative analytical analysis of scientific policy regulation. It does so by arguing that while notionally subscribed to the precautionary principle, the UK and Dutch authorities have been reluctant to use it.