This article focuses on the medical device specific aspects of clinical investigations and does not aim to be a comprehensive introduction to clinical trials. We highlight the key differences to clinical studies of medicinal products in the context of regulatory requirements in Europe, and discuss which documents are connected to the Clinical Investigation Plan. Finally, we discuss the different types of clinical investigations and the current status of the Clinical Investigation and Performance Studies module of EUDAMED (European Database for Medical Devices). Medical Writing. 2023;32(1)58-64. https://doi.org/10.56012/tpkn1389