Electronically excited O-3 and O-3.N-2 dimer are proposed as contributors to the N2O quantum yield, phi(N2O), following UV photolysis of O-3 in O-3/O-2/N-2 mixture. At 100 to 900 torr N-2 pressures, phi(N2O) is dominated by the electronically excited O-3. In this pressure regime phi(N2O) in the 310less than or equal tolambdaless than or equal to340 nm region could, potentially, exceed phi(N2O) in the lambda<310 nm region. The "classical" O(D-1), N-2 association predominates above 10 atm. The O-3.N-2+hnu may dominate at high pressures (greater than or similar to500 atm) if the temperature is very low (less than or similar to50 K). The atmospheric importance of N2O production via the classical mechanism is well known to be insignificant. In contrast, the production from excited O-3 appears to have the potential to significantly affect our current understandings of stratospheric coupled NOx-O-3 chemistry and the climatologically important N2O source-sink budget. It is therefore critical to determine the wavelength variation of phi(N2O) in the 310less than or equal tolambdaless than or equal to340 nm region by gas phase experiments. Theoretical studies are needed to understand, at the quantum chemistry level, the mechanism of the suggested N2O formation from ultra-short-lived electronically excited O-3.