Using an original database of 614 judgements in the French supreme courts from 1956 to 2010, we test for possible biases in judges’ decisions in the field of environmental accidents, focusing on a difference in treatment between private parties and the government as litigant. Two separate institutions deal with environmental cases in France, namely the Conseil d’Etat (Supreme Administrative Tribunal) for public utilities and central and local government, and the Cour de cassation (Supreme Civil Court) for private firms. We run bivariate Probit regressions to explain pro-defendant decisions and reversals of decisions. Overall, courts treat plaintiffs and defendants differently. A pro-defendant decision and a reversal of decision are less likely to occur: (i) when the appeal is initiated by the defendant rather than by the plaintiff; (ii) in the Conseil d’Etat ´ rather than in the Cour de cassation. The Conseil d’Etat ´ is harsher with defendants than the Cour de cassation. These results could be indicative of a bias of the lower administrative tribunals in favor of public utilities and/or the government.