Confirming a 1994 sentence and the 15 years in jail, Zana and her co-defendants - Hatip Dicle, Orhan Dogan and Selim Sadak - were not in the courtroom when the verdict was announced on Wednesday.
Winner of the European Parliament's 1995 Sakharov prize, the former lawmaker and her three colleagues were sentenced to complete their jail terms.
In 2001, the European Court of Human Rights ruled that the trial against the four had been unfair.
The court said the four had been unable to have key witnesses questioned and had not been informed in time of changes to the charges against them.
Ankara permitted a retrial in March 2003 under democracy reforms adopted to bring itself in line with the EU.
But defence lawyer Yusuf Alatas said the defendants had decided to boycott proceedings in protest at the progress of the trial and the court's refusal to grant them release.
Zana and her co-defendants - all MPs from the now-defunct pro-Kurdish Democracy Party (DEP) - were sentenced for membership of the outlawed Kurdistan Workers Party (PKK).
The PKK led a 15-year bloody campaign for Kurdish self-rule in the country's mainly-Kurdish southeast, which claimed more than 36,000 lives.
US listed the latest incantation
of PKK as 'terrorist' organisation
It declared a ceasefire in September 1999, after the capture of its leader Abd Allah Ocalan, and has since twice changed its name and vowed to pursue peaceful means for greater rights for Turkey's Kurds.
All four have announced their intention to appeal and go to the European Court of Human Rights a second time.
As the first Kurdish woman to win a seat in Turkey's parliament, Zana has long been a focus for international rights campaigners.
They insist her conviction was a result of Ankara's determination to silence even peaceful activists advocating Kurdish independence.