Post-Market Surveillance (PMS) is one of the most important EU MDR (2017/745) compliance requirements. It refers to monitoring the Medical device after it is introduced into the market and used by public members. Though the conformity of the device to general safety and performance requirements is demonstrated during the premarket phase, at that time, it is not always possible to gather all the data related to the safety and performance as some rare complications and risks manifest with the widespread and long term (regular) use of the device. To detect these problems, we need a system of reporting for receiving feedback about our medical device-So we need PMS. According to MDR, post-market surveillance’ means all activities carried out by manufacturers in cooperation with other economic operators to institute and keep up to date a systematic procedure to proactively collect and review experience gained from devices they place on the market, make available on the market or put into service to identify any need to apply any necessary corrective or preventive actions immediately. The ultimate goal of PMS is to continuously guarantee the safety, efficiency and quality of marketed medical devices with appropriate risk/benefit profiles. So, by conducting PMS, we ensure no undetected safety problems and uncontrolled risks with the device. PMS is compulsory for all medical devices. But its requirements vary depending on the risk class of the device. Manufacturers of class I devices are required to prepare a PMS report (PMSR) consisting of results and conclusion of post-market surveillance data along with the explanation and description of corrective and preventive actions to be taken. The PMSR should be updated when necessary and produced to the competent authority upon request. For class IIa, IIb, and III devices, a Periodic safety update report (PSUR) should be prepared as per the new EU regulation. PSUR should also include risk analysis and a description of any CAPA actions taken for the medical device on the market like PMSR. In addition to that, it should also include conclusions from the benefit-risk assessment, main PMCF findings (if any), the volume of sales of the device and an approximate estimation of the size and other features of the population using the product and frequency of their usage if possible. For Class IIa devices, the PSUR must be produced/updated at least once in two years, whereas it must be updated at least annually for Class IIb and Class III devices. Additionally, the updated PSUR must be submitted to the Notified Body for review via the EUDAMED database for Class III devices. Related - A medical device company practical guide to the PMCF requirements of the EU MDR