Two structurally similar and highly active glycopeptides have been isolated from extracts of yellow jacket venom sacs by ion-exchange and droplet countercurrent chromatography procedures. Vespulakinin 1 (heptadecapeptide) and vespulakinin 2 (pentadecapeptide) are both highly basic and contain the nonapeptide bradykinin at their carboxy termini. Most unique is the presence of carbohydrate. Vespulakinins are the first reported naturally occurring glycopeptide derivatives of bradykinin and the first reported vasoactive glycopeptides.