Ditopic dynamic combinatorial libraries were generated and screened toward inhibition of the bifunctional enzyme HPr kinase/phosphatase from Bacillus subtilis. The libraries were composed of all possible combinations resulting from the dynamic interconversion of 16 hydrazides and five monoaldehyde or dialdehyde building blocks, resulting in libraries containing up to 440 different constituents. Of all possible acyl hydrazones formed, active compounds containing two terminal cationic heterocyclic recognition groups separated by a spacer of appropriate structure could be rapidly identified using a dynamic deconvolution procedure. Thus, parallel testing of sublibraries where one specific component was excluded basically revealed all the essential components. A potent ditopic inhibitor, based on 2-aminobenzimidazole, was identified from the process.