The opposition party Vetevendosje is adamantly against the agreement with Montenegro, signed in 2015, claiming it will wrongly surrender some 8,000 hectares (30 square miles) of Kosovo's territory to its neighbor.
The Self-Determination party has used tear gas and similar tactics to disrupt votes in the past.
Opposition politician Albulena Haxhiu said they were determined to stop parliament passing the deal.
Parliament speaker Kadri Veseli said the session will continue when the situation in chamber returns to normal, according to a live video stream from the parliament.
November 2012 - Kosovo and Montenegro start consultations on signing an global agreement on border demarcation. "MPs, vote for the future, not for the past!"
The tactic has been used by the party to prevent votes in the past.
Police arrested a small group of opposition lawmakers.
Police also searched every person entering the chamber.
The proposed deal is a precondition set by the European Union to give Kosovo's citizens the ability to travel freely inside a European visa-free zone. In order for it to be approved, two-thirds of lawmakers must support it.
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"Voting for (the ratification) does not endanger Kosovo's territory", said Haradinaj, who opposed the deal before taking over as prime minister a year ago. The government and worldwide experts have disputed the claim.
U.S. Ambassador to Kosovo Greg Delawie condemned the release of the tear gas and encouraged lawmakers to carry on with voting.
The assembly of Kosovo ratified on Wednesday the agreement on border demarcation agreement with Montenegro.
Prime Minister Ramush Haradinaj told deputies Tuesday that the vote was "one of the most important matters for the country".
But a parliament majority can not be secured unless enough votes are gathered from the opposition ranks.
The ethnic Serb community's Serb List party with 10 seats wasn't present.
The deal was hammered out in 2015.
Kosovo declared independence from Serbia in 2008 and wants to join the European Union in the future, the Independent said.
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But new sanctions would need the support of all 28 European Union member states and could complicate new business deals with Iran.