About 100 trucks imposed a go-slow pace on several highways heading into the Belgian capital during the morning.
Unions and truckers' groups say that the open borders within the European Union are not matched by harmonized social legislation and that's disrupted the market in the richer, western member states.
Some 500 truckers also gathered close to the Brussels ring road to protest the conditions.
Under the slogan ''Equal wages for equal jobs!" they called on the EU to clamp down on illegal practices with tougher checks, and make sure that east European truckers get the same pay as those in Western Europe.
''This action is absolutely not targeted against eastern truckers since these people only try to make ends meet," said Frank Moreels of the ABVV socialist union.
He said the truckers from Poland, Romania and Bulgaria are often shipped in to countries like Belgium where they work for half-pay or less, forced to work in unacceptable conditions by mailbox companies who set up in eastern Europe only to escape social benefit legislation set up in wealthier countries.
''They are exploited. They sleep in their trucks or caravans for months and are badly paid compared to social standards here," Moreels said.
He added that at the same time legitimate local companies went out of business because they could not match the prices of the foreign trucking firms.
''Either the truck drivers here lose their job or their working conditions quickly worsen." Moreels said.
Belgian trucker Kris Fruru drove into Brussels in one of the convoys to protest how tough life had become for him.
He complained about east European drivers getting the cheapest conditions to drive Belgian roads while he still had to go through all the expensive, official channels in Belgium.
''We have put money into it before we get rolling and that is why all our jobs are gone at the moment," he said. ''International driving in Europe will no longer be for the western European people."
The European Parliament is currently debating laws to counter such practices in which companies take shelter in member states with the least social legislation and then send workers to the wealthy nations to undercut social standards there.
''We all back an open transport market," said European Parliamentarian Ivo Belet. ''But it is only workable if there is fair competition, including the respect for key social legislation rules."