In the course of our screening program for antifungal substances, we have found a novel cyclic tetrapeptide antibiotic named glomecidin (1, Fig. 1) in the fermentation broth of Streptomyces sp. H698 SY2. The strain was isolated from a soil sample collected in Kochi, Japan and was later classified to belong to Streptomyces lavendulae on the basis of taxonomic characterizations.1,2) In this paper, we report the production, isolation, structure elucidation and biological activities of glomecidin (1).