Anguillosporal [1], a new antifungal and antibacterial metabolite, has been isolated from the freshwater fungus Anguillospora longissima (CS-869-1A). Its structure was determined as 2,4-dihydroxy-3-ethyl-6-(1'-methylpentyl)-benzaldehyde on the basis of ms, 1H-nmr, and 13C-nmr data.