"It's a symbolic act reflecting the scope of human rights violations and a worsening situation of ensuring human rights in Russia and the government's attitude to human rights. It's symbolic and should be valued negatively," Grybauskaitė said in response to a question at a joint press conference with visiting German President Joachim Gauck.
According to the Lithuanian president, the EU does not have a common position as yet on whether to introduce sanctions against Russian officials linked to Magnitsky's death in detention, similar to those introduced by the United States.
"The EU does not have a common position as yet on the introduction of potential sanctions. And in response to the very fact of conviction, so it, obviously, concerns us," Grybauskaitė said.
On Thursday, a Moscow court found late Magnitsky and his former employer William Browder, head of investment fund Hermitage Capital, guilty of tax evasion.
Magnitsky's death in detention in 2009 became a symbol of violations in Russian prisons.
German President Gauck said he was not aware of the case details but said that Europe should "intensify discussions with Russia on the rule of law."
"Russian courts are not as independent as they are in Western Europe," he told the press conference in Vilnius.
"We in the West have no conscience whatsoever about reminding the governments of those post-Soviet countries again and again that they still have a lot of work to do to ensure the rule of law," the German president said.