The reactivity of a PNP cobalt(I) complex towards the nitrous oxide N-heterocyclic carbene adduct (NHC-N2O) was explored. Several products were isolated including the cobalt nitrosyl complex (HPNP)Co(NO) (1) and the NHC-derived imine NHC=NH (2). This study provides a rare example of metal-mediated rupture of the N-N bond in a nitrous oxide derivative, a route that could be used to generate late-metal nitrosyls.