The results of the most recent investigation of triterpenoid-based antiviral agents effective namely in the HIV-1 and HSV-1 treatment were reviewed and summarized. Several key historical achievements are included to stress consequences and continuity in this research. Most of the agents studied belong into a series of compound derived from betulin or betulinic acid, and their synthetic derivative called bevirimat. A termination of clinical trials of bevirimat in the Phase IIb initiated a search for more successful compounds partly derived from bevirimat or designed independently of bevirimat structure. Surprisingly, a majority of bevirimat mimics are derivatives of betulinic acid, while other plant triterpenoids, such as ursolic acid, oleanolic acid, glycyrrhetinic acid or other miscellaneous triterpenoids, are relatively rarely involved in a search for novel antiviral agent. Therefore, this review article is divided into three parts based on the leading triterpenoid core structure.