Royleanumioside (1), a new lupane type triterpenoid, was secluded from the CHCl3 soluble fraction of Teucrium royleanum. The structure of royleanumioside (1) was ascertained by spectral studies including 1D and 2D NMR spectroscopy and by the assessment with the reported data in literature. This new identified compound 1 was further tested for its phytotoxic activity against lettuce seedlings. Interestingly royleanumioside (1) had shown moderate phytotoxic activity.