Phytochemical study on the methanolic extract of Sansevieria cylindrica aerial parts lead to the isolation, characterization and structure elucidation of a new steroidal saponin, 1b-hydroxy-kryptogenin-1-O-a-L-rhamnopyranosyl-(1 ! 2)-a-L-arabinopyranoside (1), a new homoisoflavanone, (3S)-3,7-dihydroxy-8-methoxy-3-(30 ,40 -methylenedioxybenzyl) chroman-4-one (2) and the known saponin alliospiroside A (3). To the best of our knowledge, the genin 1b-hydroxy-kryptogenin is reported here for the first time. The structures of the new compounds were determined by UV, IR, EIMS, HRESIMS together with 1D ( 1 H and 13C) and 2D (HSQC and HMBC) NMR spectral analysis. The isolated compounds 1–3 were tested for their radical scavenging activity (DPPH). Compound 2 exhibited activity compared to that of ascorbic acid as a standard. The cytotoxicity of the isolated compounds and the standard doxorubicin was tested against the three human tumor cell lines HT116, MCF-7 and PC-3. The results showed that the isolated compounds were inactive.