Phytochemical investigation of the whole plants of Tacca plantaginea led to the isolation of 3 new withanolides and one new withanolide glucoside, named plantagiolides K-N (1-4), together with one known withanolide, 4 known withanolide glucosides, and 2 known taccalonolides. Their structures were elucidated by extensive spectroscopic analysis. Compound 4 is the first withanolide glycoside which the sugar moiety is attached at C-7. The effects of the some of isolates on TNFα-induced NF-κB transcriptional activity and cytotoxicity were evaluated.