Iceland tops the rankings, followed by Denmark and New Zealand. Relatively small and stable democracies make up the top ten most peaceful countries, the institute said in the report.
Among its neighbours, Slovenia is beaten only by Austria, which ranks fourth, while other neighbouring countries lag far behind – Hungary took 23rd place on the index, Croatia is 28th and Italy 34th.
The index is composed of 22 indicators, ranging from a nation's level of military expenditure to its relations with neighbouring countries and the level of respect for human rights.
Slovenia got its lowest marks in funding for UN peacekeeping missions, level of perceived criminality in society, number of police and security officers, organised internal conflicts, violent protests, relations with neighbouring countries and number of external and internal wars fought.