<jats:p>By a combination of 1D and 2D <jats:sup>1</jats:sup>H‐ and <jats:sup>13</jats:sup>C‐NMR, FAB‐MS, and chemical and enzymatic reactions carried out at the milligram level, it has been demonstrated that syringomycin E, the major phytotoxic antibiotic produced by <jats:italic>Pseudomonas syringae</jats:italic> pv. <jats:italic>syringae</jats:italic>, is a new lipodepsipeptide. Its amino acid sequence is Ser‐Ser‐Dab‐Dab‐Arg‐Phe‐Dhb‐4(Cl)Thr‐3(OH)Asp with the β‐carboxy group of the C‐terminal residue closing a macrocyclic ring on the OH group of the N‐terminal Ser, which in turn is <jats:italic>N</jats:italic>‐acylated by 3‐hydroxydodecanoic acid. Syringomycins A<jats:sub>1</jats:sub> and G, two other metabolites of the same bacterium, differ from syringomycin E only in their fatty acid moieties corresponding, respectively, to 3‐hydroxydecanoic and 3‐hydroxytetradecanoic acid.