Croatia joined the EU on July 1, 2013. As with other countries that applied for EU membership and negotiated the accession, competition rules have been of essential to the integration process. EU competition rules are part of acquis communautaire, which must be adopted and implemented before the accession to the end that a country can show the capacity and willingness to enforce those after it becomes a full EU member. To fulfill the criteria required for the EU accession, Croatia adopted its third Competition Act, which reflected the necessary framework, in 2009. The Act was amended on June 24, 2013 to enable the Croatian Competition Agency to directly apply Articles 101 and 102 TFEU. In addition, the right to damages arising from infringements of competition law has been introduced by the last amendments. This paper gives an overview of implications for competition law enforcement after the accession, provides comments on the enforcement capacity, overview of noteworthy amendments to the Competition Act as well as some other new legislative instruments related to the competition sphere. In addition, it discusses several important issues related to standards applied in the assessment of merger cases, and instruments necessary for the cartel enforcement. Last but not least, it explains changes in competencies for the Croatian Competition Authority.