Isorubijervosine (C33H53O7N), a new glucosidic alkaloid, as well as the known glucosides pseudojervine and veratrosine, was isolated from Veratrum eschscholtzii Gray. On acid hydrolysis, isorubijervosine yielded the aglycone isorubijervine and D-glucose. The structure of isorubijervosine was established as 3(β)-D-glucosyl-Δ5-solanidene-18-ol through methods including acetylation, hydrolytic cleavage, hydrogenation, oxidation, and comparison of physical constants (melting point, specific rotation), elemental analysis, and infrared spectra with authentic samples. Pseudojervine was isolated as an insoluble white powder from boiling ethanol extracts of fraction II, while veratrosine was obtained from methanol crystallization of column chromatography fractions. The glycosidic character of isorubijervosine was confirmed by a positive Fehling test after acid hydrolysis, and the site of D-glucose attachment at the 3(β)-hydroxyl of isorubijervine was verified by its inability to form a digitonide and conversion to solanidane-3-one-18-acetate.