The Czech Republic has missed the transposition deadline for implementing the EU Unfair Trading Practices Directive in business-to-business relationships in the agricultural and food supply chain. Yet, business relationships between a buyer (the Hruška retailer) and several suppliers of food products have already witnessed breaches of that Directive. These had to be assessed by the Czech Competition Authority also under the applicable Czech legislation, which is the Significant Market Power Act. The paper concludes that the Czech Competition Authority conducted a legal assessment of the case in compliance with the EU Directive. Also, this contribution summarizes the current stage of progress towards achieving full transposition of the EU Unfair Trading Practices Directive into the Czech domestic legal order by way of amending the current Significant Market Power Act. Completing the transposition of the Directive as soon as possible is essential in order to stop the infringement procedure lodged by the European Commission against the Czech Republic in this respect.