The article presents the identification and characterization of LaeA, a nuclear protein in *Aspergillus* spp. that regulates secondary metabolism. LaeA is essential for the expression of metabolic gene clusters, including those for sterigmatocystin (a carcinogen), penicillin (an antibiotic), and lovastatin (an antihypercholesterolemic agent). Deletion of *læA* (Δ*læA*) blocks the expression of these gene clusters, while overexpression of *læA* increases their transcription and subsequent product formation. LaeA expression is negatively regulated by AfIR, a sterigmatocystin Zn2Cys6 transcription factor, and by protein kinase A (PkaA) and RasA. Despite these negative regulators, Δ*læA* strains show little difference in spore production compared to wild-type strains, indicating that LaeA primarily regulates metabolic gene clusters. The study highlights the complex regulation of secondary metabolite production and provides a means to enhance the production of pharmaceuticals or eliminate fungal toxins by manipulating LaeA in filamentous fungi.The article presents the identification and characterization of LaeA, a nuclear protein in *Aspergillus* spp. that regulates secondary metabolism. LaeA is essential for the expression of metabolic gene clusters, including those for sterigmatocystin (a carcinogen), penicillin (an antibiotic), and lovastatin (an antihypercholesterolemic agent). Deletion of *læA* (Δ*læA*) blocks the expression of these gene clusters, while overexpression of *læA* increases their transcription and subsequent product formation. LaeA expression is negatively regulated by AfIR, a sterigmatocystin Zn2Cys6 transcription factor, and by protein kinase A (PkaA) and RasA. Despite these negative regulators, Δ*læA* strains show little difference in spore production compared to wild-type strains, indicating that LaeA primarily regulates metabolic gene clusters. The study highlights the complex regulation of secondary metabolite production and provides a means to enhance the production of pharmaceuticals or eliminate fungal toxins by manipulating LaeA in filamentous fungi.