In a country where almost a quarter of people ages between 15 and 64 smoke, Slovenia is also clamping down on tobacco advertising in an attempt to reduce these figures.
"Every day, 10 people in Slovenia die on account of smoking and we lose as much as 5% of GDP (or 1.8 billion euros) on account of it," Health Minister Milojka Kolar Celarc said.
The law, which was passed unanimously, will also prohibit advertising of tobacco products and showing those products on TV show and at public events aimed at under-eighteens.
"Smoking killed more people than both world wars yet it is still being shown to people under age as something that is quite ordinary and socially acceptable," Celarc said, adding Slovenia aimed to become a country where smokers will represent less than 5 percent of the population.
Slovenia joins Australia, France, Hungary, Ireland, New Zealand, Norway and United Kingdom in passing plain packaging legislation.