Phytochemical investigations of the rhizomes of Smilax scobinicaulis led to the isolation of seven steroidal saponins (1–7) of which four (1, 3, 4 and 6), nameed, Smilscobinosides C-F, respectively) are new. Five of these steroidal saponins with l-arabinose moiety are reported here for the first time in the genus Smilax. The structures were elucidated by spectroscopic analysis of the isolates and their hydrolysis products. The isolated compounds were evaluated for their cytotoxicity against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116 and Lovo). Compounds 3 and 4 exhibited significant inhibition on HCT-116 (with IC50 values of 10.5 and 7.8μM) together with inhibition on SGC-7901 (with IC50 values of 21.4 and 15.8μM), respectively.