The legal environment of professional sports in Europe has been recently complemented by regulations adopted by sports federations and professional leagues aiming at preserving fairness in sports competitions and/or the economic viability of this sector (like the salary cap put in place in French professional rugby union from the 2010–2011 season and the UEFA’s financial fair play regulations). No formal decisions have been taken so far by the European Commission and the French competition authority on the compliance of salary cap regulations or other similar regulation tools with competition rules. Given this context, the decisions of the New Zealand’s competition authority (“Commerce Commission”) dealt with in this article are interesting as they relate to the salary cap put in place as from 2006 by the New Zealand Rugby Football Union in the domestic inter-provincial rugby competition. More particularly, the Commerce Commission’s first decision, dated 2 June 2006, is highly interesting as the Commerce Commission carried out an in-depth legal and economic analysis to authorise the entry into effect of the salary cap pursuant to competition rules applicable in New Zealand. While these decisions should be analysed under the specific sporting and legal background of New Zealand, it is interesting to investigate what could be their practical and legal impact in Europe.