A new benzodiazepine, sclerotigenin (1), was isolated from organic extracts of the sclerotia of Penicillium sclerotigenum (NRRL 3461) along with two known griseofulvin analogues. The structure of 1 was determined primarily by analysis of 1H NMR, 13C NMR, HMQC, and HMBC data. Compound 1 was the major component of the CH2Cl2 extract of P. sclerotigenum sclerotia and is responsible for most of the antiinsectan activity of the extract against the crop pest Helicoverpa zea.