The Austrian food retail industry has been in the focus of the Federal Competition Authority (BWB) for years. The very much above-average concentration in food retailing, where three main players currently share 85% of the market, facilitates vertical price fixing, which is prohibited by antitrust law. These cartels can potentially lead to difficult market conditions for food manufacturers and food suppliers and last, but not least, also bring disadvantages for consumers.In this thesis, the very basics of antitrust law, which can be found in Article 101 TFEU and § 1 of the Austrian cartel law (KartG), as well as the conditions for block- and individual exemptions of commercial actions, are explained. Since vertical price fixing complies with the terms of „hard-core restrictions“ of the Vertical Block Exemption Regulation, it is very likely to have negative consequences for the market, which are also discussed in this thesis. The various forms of price collusion matching the definition of this form of cartel are also listed and explained. Thereafter, the historical development of antitrust enforcement in Austria and the powers and investigative activities of the BWB in Food retailing are presented. In its practice, the Competition Authority experienced that investigations in the highly concentrated Austrian food industry cause problems: the market participants were initially uncooperative, since due to the large power of food retailers the fear of negative consequences prevented incriminating statements. Through increased use of investigation methods like house searches, leniency programmes and settlements with cartel members, the actions of the BWB grew more and more successful, and the BWB has established itself as a serious authority most recently by the landmark decision of the Supreme Cartel Court in the case BWB versus Spar Austria, endorsing and legitimating the previous practice of the BWB in almost every perspective.