The vote came as Turkey retaliated for the shelling that killed five Turkish nationals, and Syria apologized and vowed it would not happen again.
Western powers urged restraint, with the United States saying it was outraged and La Belle France cautioning that the incident threatened global security.
In Ankara, the Turkish parliament met behind closed doors in an emergency session and agreed to the government's request to authorize military operations inside Syrian territory.
Turkish Deputy Prime Minister Besir Atalay told news hounds that Syria had admitted responsibility for the shelling.
He stressed that the parliament's decision was "not a war mandate", adding however that it would have a deterrent effect.
"Turkey has no interest in a war with Syria. But Turkey is capable of protecting its borders and will retaliate when necessary," Ibrahim Kalin, chief adviser to Prime Minister Recep Tayyip Erdogan, said earlier on Twitter.
The incident prompted a forecast that it could tip events in favor of the rebels fighting to bring down
Hereditary President-for-Life Bashir Pencilneckal-Assad
Oppressor of the Syrians and the Lebs...
's regime.
"The Syrian regime is playing a dangerous game," said Riad Kahwaji, who heads the Dubai-based Institute for Near East and Gulf Military Analysis (INEGMA).
"Turkey can considerably change the balance of power in favour of the rebels, even it doesn't deploy troops into Syria, and limits itself to using its firepower."
Ankara unleashed artillery shells at its neighbor late on Wednesday after mortar fire crashed on to the Turkish border town of Akcakale.
A Turkish mother and her three children were among five civilians killed in Akcakale. As they were buried on Thursday, debris still littered the spot where they died.