Reactions of imidogen, NH, in the electronically excited α 1Δ and ground X 3Σ- states with NO have been studied at 300 ± 2 K and at 20 Torr (Ar). NH(α 1Δ) and NH(X 3Σ- ) were produced in the 193 nm photolysis of HNCO and CHBr3/NO, respectively, and detected by the laser-induced fluorescence (LIF) technique. Rate constants have been measured under pseudo-first-order conditions by scanning the time delay between the photolysis and probe laser pulses. Overall rate constants were determined: [4.8 ± 0.1 (2σ) ] × 10-11 cm 3 molecule-1 s-1 for NH(α 1Δ) + NO; [4.7 ± 0.6(2σ)] × 10-11 cm3 molecule-1 s-1 for NH(X 3Σ- ) + NO. The ratio of electronic quenching, NH(α 1Δ) + NO → NH(X 3Σ- ) + NO, to the overall reaction has been obtained to be 0.53 ± 0.1. An interesting specificity for the products from different spin states of the reactants has been found from observation of OH concentration profiles. NH(X 3Σ- ) + NO produces OH + N2 exclusively, while NH(α 1Δ) + NO is over five times less effective in producing OH + N2. Profiles of H atoms detected by the vuv LIF technique indicated that H atoms are directly produced in the reaction NH(α 1Δ) + NO but not in the reaction NH(X 3Σ-) + NO.