A strain of actinomycetes identified as Pseudonocardia compacta subsp. helvetica produced new glycopeptide antibiotics, helvecardins A and B. They were isolated from culture broth mainly by affinity chromatography of D-alanyl-D-alanine and preparative HPLC. The physico-chemical properties of helvecardins A and B showed that they resemble each other. Though helvecardin A was structurally related to beta-avoparcin, it clearly differed in the presence of an O-methyl moiety in its NMR spectrum.