Bacterial toxins cause devastating diseases in humans and animals, ranging from necrotic enteritis to gas gangrene and tetraplegia. While toxin synthesis probably offers bacteria a selective advantage in competitive or hostile settings, toxigenesis is likely to represent a fitness cost to the bacterium. Therefore, bacterial populations probably adjust toxin production to competing metabolic requirements, and non-competitive environments select for phenotypes with silenced toxin production machinery. Understanding the genetic and cellular strategies bacteria use to attenuate toxin production in response to their environment is a key to interventions for disease prevention, antitoxin and vaccine development, and food and feed preservation. The overall objective is to understand the process of bacterial toxin production in its entirety, including the environmental and nutritional triggers that provoke or discourage bacteria to toxin production; how bacterial cultures coordinate toxin production and related or coupled traits; which genetic, regulatory and metabolic events direct the synthesis of toxins; how toxins are synthesized and transported; and eventually, why toxins are produced.