This Practice Note outlines the process which must be followed and the key considerations which should be contemplated when identifying the defendant(s), and any co-defendants, to a medical negligence claim. It begins by outlining the structure of the Health Service Executive (HSE) and distinguishing between public, private and semi-private entities, including the legal implications of pursuing a medical negligence claim against each. It provides an overview of essential steps taken when commencing medical negligence litigation, namely, issuing letters of claim, naming defendant parties and adding parties to proceedings. Further, this Practice Note identifies which entities and practices fall within the ambit of Ireland’s Clinical Indemnity Scheme, outlines under which circumstances a hospital or clinic can be deemed vicariously liable and illustrates what gives rise to a ‘non-delegable duty’ on the part of a medical institution.