The ruling of the Hague-based court, adopted by 15 votes to one, finds that Greece, by objecting to the admission of the Macedonia to NATO in April 2008, has breached its obligation not to block the country's accession to international organizations, if the country is referred to as "the former Yugoslav Republic of Macedonia" (FYROM).
Claims by Greece that the court has no jurisdiction to rule on the dispute have also been rejected.
Although Macedonia is recognised as the constitutional name by all EU countries except Greece, the name dispute has led to an impasse in the country's membership of both the EU and NATO.
The International court ruling is more of a symbolic nature, as it cannot impose fines on Greece or force it to refrain from similar moves. However, it does highlight that Athens' veto on launching accession negotiations with Skopje is even more unjustified.
Macedonia still finds itself unable to start talks with the EU, despite the fact that it received the status of candidate country as early as December 2005. Croatia, another former Yugoslav republic, obtained candidate status in 2004, opened negotiations in 2005 and will sign an accession treaty on Friday.
"The ruling is a step toward NATO and EU," Macedonia's foreign Minister Nikola Poposki said, as quoted by the daily Utrinski vesnik.
Poposki added that the sides should not look at each other as victors and defeated, stressing that his country's EU and NATO membership served also the interests of Greece.
"I expect that Greece will allow us to join NATO in accordance with its obligations under international law and with the support of the other NATO members," Poposki said.
However, the Greek foreign Ministry stated that the judgement did not relate, and could not relate, to the decision making process of NATO.
"Most specifically, with regard to NATO, we recall that its decisions, including those taken at the Summit in Bucharest (2008), Strasbourg (2009) and Lisbon (2010), were taken unanimously, reflecting its members shared conviction that the name issue of the former Yugoslav Republic of Macedonia be resolved before it is invited to join the Alliance," Athens insists.
Greece calls for continuing negotiations in good faith to reach a mutually acceptable solution on the name of the former Yugoslav Republic of Macedonia, expressing the hope that Skopje would begin to pursue the negotiations in good faith, as the name issue could "only be resolved through negotiation under the auspices of the United Nations."