This European Standard specifies a standardised method for sampling fish in lakes, using benthic multi-mesh gillnets. The method provides a whole-lake estimate for species occurrence, quantitative relative fish abundance and biomass expressed as Catch Per Unit Effort (CPUE), and size structure of fish assemblages in temperate lakes. It also provides estimates, which are comparable over time within a lake and between lakes. This European Standard specifies routines for sampling, data handling and reporting, and provides information on applications and further treatment of data. This European Standard also provides guidance on sampling of fish with pelagic multi-mesh gillnets and sampling of fish for age and growth analyses. Selected references in support of this European Standard are given in the Bibliography.