Eight armed men wearing masks attacked Valery Gelashvili, a member of the Republican Party, witnesses said.
The parliamentarian was hospitalized with fractures, concussions and injuries.
Leaders of Georgian opposition parties are demanding that the incident be immediately investigated and that the culprits be punished.
"The authorities are responsible for the events and should find those who severely attacked the parliament member," said David Berdzenishvili, a member of the Republican Party.
The Georgian Interior Ministry has already opened a criminal investigation into the incident. This is the second attack on a parliament member in the past several months. A member of the New Rights opposition party was recently attacked and robbed.