Abstract This article offers, for the first time, a comprehensive survey of all accessible (28) Chinese cases in which Chinese judges or lawyers invoked the Unidroit Principles of International Commercial Contracts (PICC) as applicable law or otherwise made a reference to the PICC. The survey has a particular focus on the use of the PICC to interpret or supplement domestic law, which is widely assumed to have no direct impact on the decisions of local courts. Through a detailed analysis that explores the often-times subtle connection between the PICC and judicial reasoning in Chinese courtrooms, the survey rebuts the ‘no direct impact’ thesis and demonstrates and expounds a range of significant roles the PICC may play in this respect. In doing so, this article also illustrates the case-guiding effect of previously little-known case comments—the dominant vehicle by which Chinese judges presently make the above use of the PICC.