Trust is vital for any type of collaboration, including for specialized regulatory regimes. The European Patent Office (EPO) is a fascinating case study for a specialized regulatory regime to examine trust dynamics at various levels. The EPO is not an EU agency, but it is part of an intergovernmental organization which also includes non-EU countries. The EU closely collaborates with the EPO. Since its establishment the EPO has built a very strong global reputation in patent examination. However, recent reforms to improve the EPO’s efficiency and effectiveness has had a negative impact on its reputation within the global patent community. Moreover, the last decade EPO leadership has encountered significant conflicts with its employees, which according to some commentators has resulted in a serious “trust crisis”. The objective of the paper is to examine these features and developments through the lense of multilevel trust focusing on interpersonal, interorganizational and system trust.