The 1991 Irish Competition Act may have profound effects on how business is conducted in Ireland. Two of the most important sections of the act are Section 4, which prohibits anti-competitive behavior, and Section 5, which deals with the abuse of a dominant position in the marketplace. The economic implications of both sections are addressed by examining how similar legislation has been interpreted by the courts in other jurisdictions, by US anti-trust laws in particular. The principles underpinning the act reflect those of EC competition policy, enshrined in Articles 85 and 86 of the Treaty of Rome and of US antitrust laws, namely, the Sherman and Clayton Acts. They are explicitly designed to control the abuses of monopoly power and in so doing protect competition. While the Irish Competition Act understands the need for competition policy, it appears on a first reading to have adopted a Chicagoan approach that tends to misunderstand the real world conduct of firms. Under the guise of a general law, the act may inadvertantly further the interests of a limited group rather than the general welfare. In so doing, it proffers an apology for rent-seeking behavior.