The feasibility to targeting prolidase as an antineoplastic prodrug-converting enzyme has been examined. The synthesis of proline analogues of melphalan (well known antineoplastic agent) conjugated through imido-bond (potential target for prolidase action) has been performed. One of the compounds, N-[[[[(S)-carboxy]pyrrolidin-1-yl]carbonyl]methyl]-4-[bis(2-chloro ethyl) amino]-2-phenylalanine, was found as very good prolidase substrate with susceptibility over 2 fold higher compared to standard, endogenous its substrate--Gly-L-Pro. It suggests that targeting of prolidase as a proline analogue of melphalan-converting enzyme may serve as a novel strategy in therapy of neoplastic diseases.