This contribution describes the first eutrophication assessment of the eastern North Sea using a harmonized quantitative assessment tool, so as to describe recent environmental status in response to nutrient loading pressures. The assessment tool HEAT (Andersen et al., 2010) was developed in accordance with the EU Water Framework Directive (Anon., 2000) and as a result, it is expected that this assessment meets the requirements of the EU Marine Strategy Framework Directive (MSFD; Anon., 2008) for consistent status classification of coastal waters under the two directives, as well as illustrating cooperation between countries bordering a common marine sub-region. The harmonized approach allows status changes between acceptable (non-problem area) and unacceptable (problem area) to be more precisely mapped: in previous applications of the OSPAR Comprehensive Procedure (OSPAR Comp; OSPAR Commission 2005) eutrophication status was presented as single values covering large assessment units (often national Exclusive Economic Zones) with no indication of status gradients within these regions. The present assessment resolves status variation within and across these assessment units. The eutrophication assessment highlighted limitations of some eutrophication indicators, differences in assumptions about eutrophication status between countries and also between the OSPAR COMP, Water Framework Directive and Marine Strategy approaches.