Chemical investigation on the methanol extract of the starfish Ctenodiscus crispatus resulted in the isolation of five steroids, (22E,$24{zeta}$)-26,27-bisnor-24-methyl-$5{alpha}$-cholest-22-en-$3{eta}$,5,$6{eta}$,$15{alpha}$,25-pentol 25-O-sulfate (1), (22E,24R,25R)-24-methyl-$5{alpha}$-cholest-22-en-$3{eta}$,5,$6{eta}$,$15{alpha}$,25,26-hexol 26-O-sulfate (2), (28R)-24-ethyl-$5{alpha}$-cholesta-$3{eta}$,5,$6{eta}$,8,$15{alpha}$,28,29-heptaol-24-sulfate (3), (25S)-$5{alpha}$-cholestane-$3{eta}$,5,$6{eta}$,$15{alpha}$,$16{eta}$,26-hexaol (4), and ${Delta}7$-sitosterol (5). Their structures were identified by extensive spectroscopic analyses, including 1D, 2D NMR and MS and chemical methods. Compound 4 showed cytotoxicity against human hepatoma HepG2 and glioblastoma U87MG cells via inhibition of cell growth and induction of apoptosis. Induction of apoptosis by 4 was demonstrated by cell death, DNA fragmentation, increased Bax/Bcl-2 protein ratio and the activation of caspase-3, caspase-9 and poly (ADP-ribose) polymerase (PARP).