The off-label use of medicines was discussed from various angles including sector-specific regulations, pharmacovigilance obligations, organization of the national health care systems and professional ethics. The recourse to off-label use of medicinal products is gaining importance as national health budgets are shrinking and governments are looking for more affordable means to supply health care to their citizens. Any relevant legislation or judicial interpretation should be analyzed in the light of the public health objectives. The present paper deals with the off-label use of medicines under EU competition law, through the discussion of the F Hoffman-La Roche et al v AutoritA garante della concorrenza e del mercato case, which the European Court of Justice (ECJ) has recently addressed in its explanatory ruling. The case originated from the investigation of the Italian competition authority prosecuting the anti-competitive collusion related to the suppression of the off-label use. The paper addresses the regulatory framework for off-label use in the EU and the likely effects of the ECJ's interpretation concerning pharma companies' involvement in monitoring and reporting possible health risks related to the off-label use. It demonstrates that the differences in regulatory approaches, across EU Member States, could lead to the diverging competitive conditions on the national markets for prescription drugs, reimbursed under the national health insurance systems. As a result, the competition law cases, concerning off-label use of medicinal products, would have to take into account the national specifics of these markets.