The reaction of triaminoguanidine with acetylacetone involves a sequential attack of the diketone on the hydrazine groupings of the triaminoguanidine. The reaction provides a new route to substituted tetrazines and dipyrazolyl ketone hydrazones, but it cannot be used to provide a hydrazidinating reagent comparable with the amidinating agents obtained from similar reactions of diketones with monoacylhydrazines.