A discouraging number of economic, social and environmental disasters have occurred within the United States over the past few years, all seemingly resulting from the mistakes and errors of business firms and the inattention and delays of government agencies. The blowout, explosion and fire that occurred at a deepwater oil well within the Gulf of Mexico is one example. The total collapse of the residential mortgage industry, and the ensuing economic downturn across the full country, is another. The Nature and Extent of Managerial Responsibility's focus is not on ascribing blame but on prescribing prevention. Prevention is basically simple, but it will require a considerable broadening in both the nature and the extent of managerial responsibility.