The adsorption and decomposition of NO on Ni(110) at 110 K and during subsequent heating has been studied by using low-dose, pulsed Ar+ sputtering followed by photoionization and time-of-flight mass spectrometry to monitor the surface concentration of molecularly adsorbed NO. Partial decomposition of NO occurs after adsorption at 110 K. The extent of the decomposition at 110 K is approximately described by assuming that (1) site occupation during adsorption is random, (2) decomposition of one NO poisons decomposition at three or four surrounding sites, and (3) diffusion of adsorbed NO does not occur. Approximately 20-25% of a saturation coverage decomposes at 110 K. Decomposition of the fraction of NO molecularly adsorbed at 110 K occurs during subsequent heating. These decomposition kinetics display a strong dependence on coverage. For low coverages, decomposition begins at approximately 115 K and is complete by 200 K. For a saturation coverage, decomposition is not complete until 400 K. The decomposition kinetics during heating are discussed in terms of several kinetic models including decomposition at sites exhibiting a range of activation energies.