Five new steroidal saponins were isolated from the fruits of Tribulus terrestris. Their structures were fully established by spectroscopic and chemical analysis as (23S,25S)-5alpha-spirostane-24-one-3beta,23-diol-3-O-{alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-glucopyranosyl-(1-->4)]-beta-d-galactopyranoside} (1), (24S,25S)-5alpha-spirostane-3beta,24-diol-3-O-{alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-glucopyranosyl-(1-->4)]-beta-d-galactopyranoside} (2), 26-O-beta-d-glucopyranosyl-(25R)-5alpha-furostan-2alpha,3beta,22alpha,26-tetraol-3-O-{beta-d-glucopyranosyl-(1-->2)-O-beta-d-glucopyranosyl-(1-->4)-beta-d-galactopyranoside} (3), 26-O-beta-d-glucopyranosyl-(25R)-5alpha-furostan-20(22)-en-2alpha,3beta,26-triol-3-O-{beta-d-glucopyranosyl-(1-->2)-O-beta-d-glucopyranosyl-(1-->4)-beta-d-galactopyranoside} (4), and 26-O-beta-d-glucopyranosyl-(25S)-5alpha-furostan-12-one-22-methoxy-3beta,26-diol-3-O-{alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-glucopyranosyl-(1-->4)]-beta-d-galactopyranoside} (5). The isolated compounds were evaluated for cytostatic activity against HL-60 cells.