Repeat measurements of dissolved nitrous oxide (N₂O) along two transects of the western continental shelf of India in 2012 revealed high concentrations of 45 ± 32 nM (off Kochi) and 73 ± 63 nM (off Mangalore) during the summer monsoon (SM). N₂O concentrations increased nonlinearly during the peak of the SM upwelling, when low O₂ (<25 µM) conditions prevailed in the water column. Off Kochi, N₂O levels fell gradually from the fall intermonsoon (20 ± 8 nM) to the winter monsoon (8.8 ± 2 nM) and remained low (9.2 ± 5.2 nM) through the spring intermonsoon season. The N₂O supersaturation off Kochi (574 ± 720%) was presumably due to its high yield during sediment denitrification, whereas the higher N₂O supersaturation observed off Mangalore (1046 ± 885%) was due to its production during denitrification in both the anoxic water column and the underlying sediments. Such distinctive biogeochemical behavior between these two shelf segments is at first augmented by the natural origin of intense upwelling at Mangalore relative to Kochi wherein suboxic to anoxic oxygen minimum zone waters spread from offshore to the shelf of Mangalore, over which the runoff and terrestrial nutrients supply acts in unison. Following new zonal extrapolation approach, our revised estimate of N₂O effluxes from the southwestern Indian shelf (7–14°N) was four times lower (0.019–0.039 Tg y⁻¹) than previous estimate. Nevertheless, further studies are needed to refine the N₂O effluxes from the entire western Indian shelf to monitor its modification due to expansion/intensification of the coastal low‐O₂ zones and also to ascertain its actual N₂O contribution to the world oceans.