The Surkhab, also known as the Surkh Rud, is a river in Afghanistan, which flows in the provinces of Paktia and Nangarhar.
The river flows north-east, then east, to the north of the western part of the Safed Koh mountains, from which it receives meltwater from glaciers.
It joins the Kabul River some 10 km west of Jalalabad.
The Surkhab receives many tributaries, especially on its right bank from the snows of the Spin Ghar range.
The main right tributaries of the Surkhab are the Anderab and Khanabad rivers.