The river runs to the northeast, close to the Piatra Goznei peak and through the village of Vâliug, reaching the northernmost part of the Semenic mountains, where it turns to the northwest.

It runs through the cities of Reșița and Bocșa the largest settlements on its course, and continues next to the villages of Berzovia, and Șoșdea, where the Bârzava leaves the mountain region of Banat for the lower western plain.

This is also where the river turns to the southwest, spills in several parallel streams and flows next to the villages of Sculea, Gătaia, Sângeorge, Rovinița Mare and Denta.

After it flows next to the village of Partoș, it forms the Romanian-Serbian border for a few kilometers and after the course of 127 km through Romania, the Bârzava enters the Serbian province of Vojvodina near the hamlet of Markovićevo.

[citation needed] The following rivers are tributaries to the river Bârzava (from source to mouth):[2] Left: Crivaia Mare, Grindieș, Văliug, Lișcovu Mare, Râul Alb, Secu, Sodol, Doman, Bârzăvița, Moravița (upper Bârzava), Copăș, Moscădin, Fizeș, Boruga, Gorova, Ciopa, Moravița Right: Berzovița, Alibeg, Pârâul Băilor Mari, Bolnovăț, Gozna, Izvoru Rău, Breazova, Groposu, Pietrosu, Țerova, Cremeni, Vornic, Stoiconic, Birdanca In Romania: Văliug, Reșița, Bocșa, Berzovia, Gătaia, Denta In Serbia: Markovićevo, Konak, Banatska Dubica, Jarkovac