Reaction pathways for the one- and two-electron reductions of [Fe(CN)(5)NO](2-) have been investigated by means of a density functional theory (DFT) approach combined with the polarized continuum model (PCM) of solvation. In addition, UV-vis spectroscopic data were obtained using ZINDO/S calculations including a point-charge model simulation of solvent effects. DFT methodologies have been used to assess the thermodynamical feasibility of protonation and cyanide-release processes for the reduced species. We conclude that [Fe(CN)(5)NO](3-) is a stable species in aqueous solution but may release cyanide yielding [Fe(CN)(4)NO](2-), consistent with experimental results. On the other hand, the [Fe(CN)(5)NO](4-) complex turns out to be unstable in solution, yielding the product of cyanide release, [Fe(CN)(4)NO](3-), and/or the protonated HNO complex. All the structural and spectroscopic (IR, UV-vis) predictions for the [Fe(CN)(5)HNO](3-) ion are consistent with the scarce but significant experimental evidence of its presence as an intermediate in nitrogen redox interconversion chemistry. Our computed data support an Fe-II(LS) + NO+ assignment for [Fe(CN)(5)NO](2-), an Fe-II(LS) + NO assignment for the one-electron reduction product, but an Fel(LS) + NO+ for the one-electron product after dissociation,of an axial cianide, and an Fe-II + singlet NO- for the two-electron reduction species.