The source of the Bosna river on the outskirts of Sarajevo.

The Bosna is the third longest river in Bosnia and Herzegovina, and is considered one of the country's three major internal rivers, along with the Neretva and Vrbas. The river flows for 271 kilometers (168 miles) and is found only in Bosnia. It has no foreign variations of its name, and is known as the Bosna in all three of the country's official languages, although it is sometimes spelled Vasna. In Roman times the river was called the Basana, and historians think this is the origin of the word Bosnia.

The river Bosna also makes up the Bosna River Valley, the country's industrial center and home of close to a million people, as well as the location of several major cities. The river's biggest tributaries are the Željeznica, Miljacka, Fojnica, Lašva, Gostović, Krivaja, Usora, and Spreća rivers.

The river originates in the Vrelo Bosne, on the outskirts of Sarajevo at the base of mount Igman. The spring is one of Bosnia and Herzegovina's chief natural landmarks and tourist attractions. From there it flows north until it feeds into the river Sava.

Although it does not pass through any foreign countries, the Bosna flows through a number of cantons and regions of Bosnia. From its starting point in the Sarajevo Canton, it also flows through Zenica_Doboj Canton, Doboj Region, and Posavina Canton, in that order.

On its way north the river Bosna also passes through the cities of Visoko, Zenica, and Doboj. Its most famous tributary, the Miljacka, passes through Sarajevo as well.