Phytochemical investigations of Senna tora seeds led to the isolation of fourteen phenolic glycosides, including three new compounds, namely, sennatorosides A-C (1-3). The chemical structures of the isolated compounds were confirmed by a detailed analysis of the 1D and 2D NMR, HR-ESI-QTOF mass, and ECD spectra. Among the isolated compounds, 1-[(1-(<beta>-D-glucopyranosyl)oxy-8-hydroxy-methoxynaphthalen)-6-yl]propan-2-one (11) exhibited strong cytotoxic activity against three tested cancer cell lines, SK-LU-1 (lung cancer), HepG2 (hepatoma cancer), and MCF-7 (breast cancer), with IC50 values of 8.05 +/- 0.28, 9.52 +/- 1.20, and 8.54 +/- 0.85 mu M, respectively, whereas compounds 1-4, 6-9, 12, and 14 revealed moderated or weak cytotoxicity, with IC50 values ranging from 44.59 +/- 5.03-98.24 +/- 2.45 mu M.