The swoop was part of an investigation spanning Italy, Germany, Belgium, Portugal, Spain, Slovenia, Romania, Brazil and Panama, according to European Union law enforcement agency Europol.
The network was devoted primarily to international drug trafficking from South America to both Europe and Australia, Europol said in a statement.
A total of 108 people were arrested in Italy and other EU countries on the orders of police in the southern city of Reggio Calabria, Italian police said.
Related investigations led to the arrest of 24 people in Germany, they said, as well as a further 53 detentions in northern Italy.
The interior minister of the German state of North Rhine-Westphalia said 18 of the arrests were made there.