Mr Zarakolu is to appeal against the verdict
A Turkish publisher has been sentenced to five months in prison for publishing a book by a British author about the mass killing of Armenians in 1915.
Ragip Zarakolu was found guilty of "insulting the institutions of the Turkish republic" under Article 301 of Turkey's penal code.
The controversial law was recently reformed under pressure from the EU to ensure freedom of speech in Turkey.
This is the first high-profile verdict to be handed down since then.
Mr Zarakolu's sentence seems to confirm campaigners' fears that changes to the law were merely cosmetic, says the BBC's Sarah Rainsford in Istanbul.
In April it became a crime to insult the Turkish nation, rather than Turkishness. But insulting the Turkish nation can still be punished by up to two years in jail.
Mr Zarakolu was brought to trial for publishing a book by British author George Jerjian on the mass killings of Armenians under the Ottoman Empire in 1915.
Turkey denies the killings were genocide and the issue remains highly sensitive.
Passing sentence, the judge told Mr Zarakolu he had insulted the Turkish republic and its founders. His own defence - that he had the right to criticise - was rejected.
Mr Zarakolu's case was not referred to the Turkish ministry of justice, as required under the reforms, and he has said he will appeal against the verdict, our correspondent reports.
His sentence will not be imposed until that appeal process is complete.
Outside the court, Mr Zarakolu said that such rulings had silenced many writers in Turkey but that he would continue to challenge the restrictions.
"I was partly waiting for this result. But it is a struggle for the truth and it will go on. I do not accept myself as convicted. This is a conviction for official history and for denialism," he said.
The justice ministry recently revealed that 1,700 people were tried under Article 301 in 2006 alone.