<p>Nitrous oxide (N<sub>2</sub>O) is a potent greenhouse gas and it is involved in stratospheric ozone depletion. Its oceanic production is mainly influenced by dissolved nutrient and oxygen (O<sub>2</sub>) concentrations in the water column. Here we examined the seasonal and annual variations of dissolved N<sub>2</sub>O at the Boknis Eck (BE) Time-Series Station located in Eckernförde Bay (southwestern Baltic Sea). Monthly measurements of N<sub>2</sub>O started in July 2005. We found a pronounced seasonal pattern for N<sub>2</sub>O with high concentrations (supersaturations) in winter/early spring and low concentrations (undersaturations) in autumn when hypoxic/anoxic conditions prevail. Unusually low N<sub>2</sub>O concentrations were observed during October 2016–April 2017, which was presumably a result of prolonged anoxia and the subsequent nutrient deficiency. Unusually high N<sub>2</sub>O concentrations were found in November 2017 and this event was linked to the occurrence of upwelling which interrupted N<sub>2</sub>O consumption via denitrification and potentially promoted ammonium oxidation (nitrification) at the oxic/anoxic interface. Nutrient concentrations (such as nitrate, nitrite and phosphate) at BE are decreasing since 1980s, but oxygen concentrations in the water column are still decreasing. Our results indicate a close coupling of N<sub>2</sub>O anomalies to O<sub>2</sub> concentration, nutrients and stratification. Given the long-term trends of declining nutrient and oxygen concentrations at BE, a decrease in N<sub>2</sub>O concentration, and thus emissions, seems likely due to an increasing number of events with low N<sub>2</sub>O concentrations.</p>