Tubingensin A (3), a new carbazole alkaloid biogenetically related to the aflavinines, has been isolated from the hexane extract of the sclerotia of the fungus Aspergillus tubingensis. The structure of tubingensin A, which contains an unprecedented 9H-octahydronaphtho[3,4-b]carbazole ring system, was assigned through NMR decoupling, selective INEPT, and heteronuclear shift correlation experiments. Tubingensin A exhibits activity against the widespread crop pest Heliothis zea and displays in vitro antiviral activity against herpes simplex virus type 1.