Three novel diterpenoids, excoecarins D, E, and K (1-3), were isolated from Excoecaria agallocha. The structures of 1-3 were established as 3alpha,18-dihydroxy-3beta,20-epoxybeyer-15-ene, (15R, 16S)-ent-15,16-epoxybeyeran-3-one, and ent-3beta-hydroxykaur-16-en-2-one, respectively, on the basis of extensive NMR experiments and, in the case of 1, by X-ray analysis.