Examination of vertical profiles of N2O, oxygen, and nitrate from the Northeast and Northwest Atlantic, Northeast Pacific and eastern tropical North Pacific reveals a striking consistency in the relationships among them. With the exception of zones of active denitrification, N2O is negatively correlated with oxygen and positively correlated with nitrate throughout the water column and it is, therefore, concluded that N2O production in the ocean is associated with the oxidative regeneration of nitrate. In both the Atlantic and Pacific Oceans, the difference between the measured N2O concentration and its equilibrium solubility is linearly correlated with apparent oxygen utilization and from this relationship and the Redfield plankton decomposition model it is estimated that N2O-nitrogen comprises about 0.1 to 0.4% of the nitrogen regenerated in the ocean. From the ratio of N2O to nitrate production during nitrate regeneration and estimates of the overall regeneration of nitrate in the ocean, it is concluded that the total marine production of N2O is in the range of 4 to 10 Tg-N yr-1 (6 to 16 Tg-N2O yr-1). This estimate is in good agreement with estimates of the N2O loss to the atmosphere derived from N2O measurements at the sea surface.