Triterpenoids isolated and characterized from various sources are reviewed. The newer techniques used in their isolation and structure elucidation, the newer skeleton triterpenoids characterized, chemical modifications and synthetic studies reported are discussed. A compilation of the triterpenoids isolated during the period 1982-1989 along with their occurrence, available physical data, spectroscopy and X-ray analysis used for their characterization, is included. The biological activities of the triterpenoids are also described.