It is a right hand tributary of the Chona, and is 363 kilometres (226 mi) long, with a drainage basin of 10,100 square kilometres (3,900 sq mi).

The Russian Geographical Society organized an expedition in 1853–55 to survey the orography, geology and population of the Vilyuy and Chona basins.

It flows first westwards for a relatively short stretch, then it bends and heads roughly northwards across the middle part of the plateau, in the border area between Irkutsk Oblast and Yakutia.

Finally the Vakunayka joins the right bank of the Chona 300 km (190 mi) from its mouth in the Vilyuy Reservoir.

The river is fed by snow and rain and freezes between October and late May.