Harmonised microlitter monitoring data is fundamental to inform policy and support the implementation of the European Marine Strategy Framework Directive (MSFD) towards provisions such as reduction targets, the definition of threshold values or the determination of Good Environmental Status. EU Member States have performed a large number of surface microlitter surveys on the European Regional Seas under the MSFD. A total of 2552 single measures have been collected during the period 2012 - 2020 in close collaboration with the European Marine Monitoring and Data network (EMODnet). The analysis of the dataset should support the establishment of baselines of marine microlitter on the surface layer of the water column that enable further discussion of the definition of agreed threshold values in conjunction with EU Member States and Regional Seas Conventions.