The People's Democracy Party (HADEP) was shut down in 2003 by Turkey's Constitutional Court on the grounds that it was a "centre of illegal activities" in support of the outlawed Kurdistan Workers Party (PKK).
Some members of the PKK - which is deemed a terrorist organization by the European Union and the United States - were also banned from politics for five years for "spreading separatist propaganda."
In a statement released in Strasbourg, the ECHR said the Turkish court's dissolution of HADEP had interfered with the right to freedom of association.
It further stated that the party's activities, though at times strongly critical of the Turkish government policies towards Kurds, did not amount to inciting armed resistance or acts of violence.
Two earlier pro-Kurdish political parties in Turkey were also closed down by the Turkish high court prior to HADEP's founding, in 1994. And HADEP's successor, the Democratic Society Party (DTP), was banned in December 2009, also for alleged PKK ties.
"Turkey is a graveyard of political parties. There's a pattern of closing parties that are perceived to be pro-Kurdish or Islamist," Emma Sinclair-Webb, a Turkey researcher for Human Rights Watch, told the German Press Agency dpa.
About two dozen political parties have been closed down by Turkish courts since 1962. The ruling Justice and Development Party, which has Islamist roots, narrowly avoided being shut down in 2009 on grounds it was engaged in "anti-secularist activity."
Speaking about Tuesday's ECHR decision, Sinclair-Webb said, "The ECHR has made its point many times on this issue. It highlights again the urgent need for complete reform of the Turkish constitution."
The ECHR ruling comes in the wake of recent European Union enlargement reports which have noted that Turkey needs to make greater progress on judicial reform and freedom of expression.
Strasbourg/Istanbul - DPA