Coastal areas such as continental shelves, estuaries, deltas, fjords and lagoons can release high amounts of nitrous oxide (N 2O) and methane (CH 4) to the atmosphere. However, estimates of trace gas emissions are often biased by incomplete spatial and temporal coverages. Based on a compilation of literature data, the distributions of N 2O and CH 4 in European coastal areas (i.e. Arctic Ocean, Baltic Sea, North Sea, northeastern Atlantic Ocean, Mediterranean Sea, Black Sea) were reviewed and their emissions to the atmosphere reassessed. Maximum N 2O saturations were found in estuarine systems, whereas the shelf waters, which are not influenced by freshwater plumes, are close to equilibrium with the atmosphere. This implies that N 2O is mainly formed in estuarine systems. European coastal waters are a net source of N 2O to the atmosphere (0.33-0.67 Tg N year -1) with the major contribution coming from estuarine/river systems and not from open shelf areas. European shelf areas contribute significantly (up to 26%) to the global oceanic N 2O emissions. CH 4 saturations show a high temporal and spatial variability with maximum values in estuarine/fjord systems. European coastal areas are a source of atmospheric CH 4 (0.35-0.75 Tg C year -1) and contribute significantly to the overall global CH 4 oceanic emissions. However, this estimate still seems to be a severe underestimation since CH 4 fluxes from estuaries and shallow seeps are not adequately represented. Future N 2O and CH 4 emissions from coastal areas strongly depend on the degree of eutrophication of coastal waters and might increase in the future.