Oxygen minimum zones (OMZs), such as those found in the eastern South Pacific (ESP), are the most important N2O sources in the global ocean relative to their volume. N2O production is related to low O-2 concentrations and high primary productivity. However, when O-2 is sufficiently low, canonical denitrification takes place and N2O consumption can be expected. N2O distribution in the ESP was analyzed over a wide latitudinal and longitudinal range (from 5A degrees to 30A degrees S and from 71-76A degrees to 84A degrees W) based on 890 N2O measurements. Intense N2O consumption, driving undersaturations as low as 40%, was always associated with secondary NO2- accumulation (SNM), a good indicator of suboxic/anoxic O-2 levels. First, we explore relationships between Delta N2O and O-2 based on existing data of denitrifying bacteria cultures and field observations. Given the uncertainties in the O-2 measurements, a second relationship between Delta N2O and NO2- (> 0.75 mu M) was established for suboxic waters (O-2 < 8 mu M). We reproduced the apparent N2O production (delta N2O) along the OMZ in ESP with high reliability (r(2) = 0.73 p = 0.01). Our results will contribute to the quantification of the N2O that is recycled in O-2 deficient waters, and improve the prediction of N2O behavior under future scenarios of OMZ expansion and intensification.