The river has a wide mouth and flows into the Indian Ocean just south of Port Edward.

The Mtamvuna river is approximately 162 km long with a catchment area of 1,553 km².

[3] In 1552 a Portuguese ship ran aground at the mouth of the Mtamvuna River and a group of local people got close to the sailors wishing to trade with them.

[4] The Umtamvuna Nature Reserve is a protected area located close to the deep Mtamvuna River Gorge.

[5] Presently this river is part of the Mvoti to Umzimkulu Water Management Area.