The trial of leaders and members of the extreme-right Golden Dawn party was postponed for Tuesday 28 July.
The latest postponement was due to the inability of the alternate prosecutor to attend the session. Next Tuesday's session will be the last one before the court recess for the summer holiday according to ANA-MPA news agency.
Most of the defendants will be tried for being part of a criminal organization - a serious offense in Greece - while others are accused of crimes ranging from murder to conspiracy to murder, possession of weapons and racist violence, according to AFP news agency. Some of the defendants face sentences of up to 20 years in prison.
It comes after an investigation into the 2013 murder of a left-wing, anti-racist rapper, Pavlos Fyssas. A man held for the stabbing claimed to be a Golden Dawn supporter, though the party denied any link to him.
The extreme-right party came third in January's elections with 6.3%.