This Article frames the precautionary principle as an inner limit to the EU institutions’ broad discretion in the field of EU risk regulation, contextualizing recourse to the principle against the more encompassing backdrop of socially acceptable risk approaches. On these grounds, it inquires to what extent the precautionary principle may be successfully invoked in challenges to acts which are deemed insufficiently protective. The opening sections set the ground for the analysis. The third section analyzes challenges to regulatory acts, arguing that the Court has followed a quantitative threshold approach. This is legally tenable and appropriate; however, it cannot do justice to the true nature of the precautionary principle. The following sections analyze cases involving legislative acts. This includes an in-depth examination of the recent Blaise case, which has put judicial review of compliance with the precautionary principle under the spotlight. Against this overall background, this Article concludes that judicial review can hardly do justice to the precautionary principle, as applicable to the risk management process and underpinning EU legislative frameworks. It will ultimately rest on EU risk managers and EU legislators to ensure that the principle is applied and that its overarching goals are pursued.