UV absorption spectroscopy-guided fractionation of the culture extract of a marine obligate bacterium of the genus <i>Microbulbifer</i> yielded a novel cyclic hexapeptide, bulbiferamide (<b>1</b>). NMR spectroscopic and mass spectrometric analyses revealed the structure of <b>1</b> to be a cyclic tetrapeptide appending a ureido-bridged two amino acid unit. Notably, Trp is a junction residue, forming on one hand a very rare <i>N</i>-aminoacylated indole linkage for cyclization and on the other hand connecting the ureido-containing tail structure, which is an unprecedented way of configuring peptides. The component amino acids were determined to be l by the advanced Marfey's method. Compound <b>1</b> displayed growth inhibitory activity against <i>Trypanosoma cruzi</i> epimastigotes with an IC<sub>50</sub> value of 4.1 μM, comparable to the currently approved drug benznidazole, while it was not cytotoxic to P388 murine leukemia cells at 100 μM.