For nearly 20 years visas have been a barrier for Balkan citizens
The EU has granted visa-free travel for citizens of three Balkan countries - Macedonia, Montenegro and Serbia.
From 19 December citizens of the three former Yugoslav republics who hold biometric passports will not need visas to enter the borderless Schengen area.
The UK still requires visas, because it is outside the Schengen agreement.
The visa waiver followed measures by the three countries - all hopeful of joining the EU - to beef up border security and tackle organised crime.
Path to integration
Serbia's President Boris Tadic said it was "a practical and clear step towards European integration".
He said the move put Serbia back to where it was 20 years ago, when citizens of the then Yugoslavia did not need visas to travel to the rest of Europe.
The visa waiver does not apply to Kosovo, whose independence from Serbia is not recognised by all EU member states.
Before Balkan wars, a Yugoslav passport allowed visa-free travel to almost any country
After the wars, that changed in an attempt to stem the flow of refugees
Now up to 70% of Serbs do not have passports
The Schengen zone is made up of 25 European countries - the 27 EU members, minus the UK, Ireland, Bulgaria, Romania and Cyprus; plus three non-EU nations - Norway, Iceland and Switzerland.
Although Bulgaria and Romania are not yet in Schengen they do have visa-free arrangements with the EU, so they will also ease the travel rules for their Balkan neighbours, if they have not already done so unilaterally.
The EU governments said Albania and Bosnia-Hercegovina had not yet met all the benchmarks required for visa liberalisation.
Macedonia has been a candidate for EU membership since 2005, but its accession is being held up by a dispute with neighbouring Greece over the country's name.
Serbia's pro-Western government has been told its EU accession depends on the capture of the last two remaining major war crimes suspects, former Bosnian Serb army chief Gen Ratko Mladic and the former Croatian Serb leader, Goran Hadzic.