The law, which was passed after a heated day-long debate, contains EU guidelines for a voter threshold requirement in the upcoming independence vote that should split Montenegro from Serbia.
The law envisages that for Montenegro's move to independence to be valid, at least 55 percent of those casting ballots in the independence referendum have to vote for the departure from the current state union of Serbia-Montenegro.
In the 75-seat parliament, 60 deputies voted for the bill, ten were against it and five were absent.
Montenegrin President Filip Vujanovic hopes that the parliament that will reconvene tomorrow will also decide on the date for the referendum.
The two blocs - parties in favour of Montenegro's independent and pro-Serb parties - have already agreed with European Union mediator Miroslav Lajcak that the referendum be scheduled for 21 May this year.
If citizens do not vote for the country's independence at the referendum, another one can be held only after three years.