CIX has been established by signing the Memorandum (JPEG, 93 KB) on Establishment of National Center for Internet Traffic on the day of September 8, 2000 (Croatian Internet eXchange). Presentation from the ceremony of CIX establishing held in the building of the Croatian Chamber of Economy (PDF, 499.92 KB)

In that manner, five signatories of the Memorandum (Croatian Academic and Research Network CARNet, AT&T Global Network Services Croatia, Croatian Telecommunications, Iskon Internet and VIP - NET) have defined organisational and technical framework of CIX.

At the beginning of 2001, the CIX room was arranged on the second floor of the University Computing Center (SRCE) facility. During the arrangement of the room, all the necessary electrical (direct power supply and uninterruptible power supply) and telecommunication (copper and optical infrastructure within the SRCE) infrastructure was performed. Appropriate climatic conditions inside the room (humidity and temperature) are provided. Room access rules have been set to guarantee the physical safety of the equipment inside the room, a communication cabinet has been set up and equipped for the reception of CIX member equipment

CARNET is connected to CIX infrastructure on 3rd January 2001.
ISKON is connected to CIX infrastructure on 13th March 2001.

Since its establishment in 2000, until March 31, 2005, the work of CIX had been financed by the Croatian Academic and Research Network CARNet, as its own service, which has been designed and technically maintained by Srce.

In 2005, at the Founding Meeting of CIX Council, Srce, as a host, fully assumed CIX maintenance, thus CIX became non-profit service of Srce, which provided conditions for inter-connection and uninterrupted work of CIX 24/7 throughout a year.

In 2006, the first meeting of CIX Council was held, and in the same year, CIX received its 15th member.

At the beginning of 2008, CIX has become a new member of the European Internet Exchange Association, (acronym Euro-IX), the association of the European Centers for Internet Traffic Exchange, whose goal is promotion of the culture of open idea and experiences exchange amongst its members. That very same year, a first contract on membership and usage of CIX service has been signed with one of foreign members (VeriSign).

In May 2011, in Srce, the Google Global Cache (GGC) centre started functioning. Selection of Srce as the host of this significant infrastructure additionally emphasized the role of CIX in Internet development in Croatia.

Further, in 2011, traffic through CIX switch exceeded, for the first time, 5Gbps limit, and monthly transferred traffic in October exceeded 1PB.

On September 8th 2015 a ceremonial session held at Srce to mark the 15th year of existence and a short video regarding 15 years of CIX existence premiered.

In January 2016, Microsoft joined CIX community.