 During his time with the IIHF, Ahearne is credited with improving its finances, cooperating with the International Olympic Committee (IOC), and helping to develop and introduce hockey to new countries.He also transformed the Ice Hockey World Championships into a well-known annual tournament, and implemented the splitting of the event into different tiers of competition.He also oversaw the foundation of both the IIHF European Junior Championships and the Izvestia Cup in 1967.