About a dozen journalists rose from their seats and displayed posters condemning media censorship by the Ukrainian government during a speech by President Viktor Yanukovych.
The protest occurred on September 3 as Yanukovych addressed a meeting of the World Newspaper Congress in Kyiv.
Reports say Yanukovych did not react as the protesting journalists held up signs reading "Stop censorship."
There was no immediate comment from the president's office.
Media watchdogs say Ukrainian press freedoms have waned since Yanukovych came to power in 2010.
Jacob Mathew, president of the World Association of Newspapers and News Publishers, urged Ukrainian authorities to work to reinstate "freedoms that sustain democracy and human dignity."
Based on reporting by AP and Interfax