Molybdenum nitrides, which are used as hard coatings or corrosion and abrasion resistant layers, are in general considered as having good chemical resistance. We find, however, that molybdenum nitride Mo2N nanowires promptly react with lead nitrate in water at room temperature, resulting in formation of lead molybdate nanoparticles. Depending on the initial concentrations, the resulting material are either hybrid nanowires decorated with individual lead molybdate nanoparticles, or solely lead molybdate nanoparticles. The synthesised nanoparticles are fairly uniform in size, with diameters of up to a hundred nanometres. We find that the particle size is practically independent of the initial concentrations that we used. The performed one-step reaction, which is almost immediate and requires no additional reagents, clearly shows chemical reactivity of molybdenum nitrides and opens a new use for molybdenum nitrides as starting materials in a variety of chemical reactions. At the same time, the demonstrated reaction presents a new method for synthesis of lead molybdate nanoparticles or hybrid materials using molybdenum nitride nanowires as the starting material.