The Leitha rises in Lower Austria at the confluence of its two headstreams, the Schwarza, discharging the Schneeberg, Rax and Schneealpe ranges of the Northern Limestone Alps, and the Pitten. Between Ebenfurth and Leithaprodersdorf, and between Bruck an der Leitha and Gattendorf, the Leitha forms part of the border between the Austrian states of Lower Austria and Burgenland. East of Nickelsdorf, the river passes into Hungary, where it flows into the Moson arm of the Danube west of Szigetköz Island near Mosonmagyaróvár. Important towns on its course are Wiener Neustadt, Bruck and Mosonmagyaróvár.