In addition to the known iridoid glucosides loganin, sweroside and cantleyoside, Dipsacus sylvestris has provided 4 novel bis-iridoid glucosides named sylvestrosides I-IV, composed of swerosidic acid, secologanic acid, loganin and loganin aglucone. Sylvestroside I, II and III have been fully characterized by chemical conversions and by ¹³C NMR spectroscopy. A probable formula for sylvestroside IV is presented.