The municipality consists of several settlements:[4] In 33 BC the Romans, led by the future Emperor Octavian Augustus, won a battle against an Illyrian tribe, the Japods, in the area east of Plaški.

The second mention of the village dates from 1185 and relates to the establishment of the new Krbava diocese, which the parish of Plaški became a part of.

Another document from 1550 confirms Plaški's status as defense fort and also mentions it as one of four centres in the Military Frontier of the Habsburg Empire.

After the invasion of Yugoslavia in April 1941 Plaški was first occupied by Italian forces and then turned over to the Independent State of Croatia in late 1941.

Much of the Croat population is made up of those forced to leave Bosnia replacing Serbs who, in 1995, fled during Operation Storm.