Diageo, the makers of Baileys Irish Cream, has won the right to sell miniature bottles across the European Union.
The European Court of Justice ruled that a German liquor industry ban on 0.071 litre containers is wrong.
The court said it interpreted the relevant EU rules in light of their aim - to uphold the bloc's basic tenet of free movement of lawfully made goods.
Consumers are still protected as other EU rules required manufacturers to display the volume and unit price on the product, the court said.
Other brands of spirits are also covered by this decision, although it was Baileys and Diageo that became involved in this court case.
