<jats:p>The structure of the fuscopeptins, bioactive lipodepsipeptides produced in culture by the gramineae pathogen <jats:italic>Pseudomonas fuscovaginae</jats:italic>, has been determined. The combined use of FAB mass spectrometry, NMR spectroscopy and chemical and enzymatic procedures allowed one to define a peptide moiety corresponding to ZDhb‐DPro‐LLeu‐DAla‐DAla‐DAla‐DAlaDVal‐Gly‐DAla‐DVal‐DAla‐DVal‐ZDhb‐DaThr‐LAla‐LDabDDab‐LPhe with the terminal carboxyl group closing a macrocyclic ring on the hydroxyl group of the <jats:italic>allo</jats:italic>threonine residue. The N‐terminus is in turn acylated by 3‐hydroxyoctanoate in fuscopeptin A and 3‐hydroxydecanoate in fuscopeptin B. Some preliminary data on the biological activity of fuscopeptins are also reported.