"Mars Chocolate is carrying out a voluntary recall of chocolate products of Mars, Snickers, Milky Way and Celebrations after plastic was found in a product," the company said in a statement.
Products with a best before date from June 19, 2016 to January 8, 2017 have been affected, it said, adding that a full list can be found on its website www.mars.de.
"With this recall, we would like to prevent consumers who have purchased one of the above-mentioned products from consuming it," said Mars.
The US chocolate maker produces around 10 million snacks daily at its factory in western Germany's Viersen.
A spokesman was unable to say if Tuesday's recall was the biggest ever in the company's history.
The US giant's Dutch subsidiary also issued a call-back for similar products with the same expiration dates, Dutch news agency ANP said.
The products covered by the Dutch recall were all made at a factory in Veghel, in southern Netherlands, ANP said.