It has two main sources:[2] the Ruvu, which rises as Lumi at Kilimanjaro, passes through Lake Jipe, and empties into the Nyumba ya Mungu Reservoir, and the Kikuletwa River, coming from the west and mainly fed by rivers of Mount Meru in Arusha Region, which also enters into the Nyumba ya Mungu Reservoir in Kilimanjaro Region.

[6] Nowadays that has been settled as "Pangani" from the Nyumba ya Mungu reservoir to the Ocean.

The stream is strongest above Koleni, within 5 miles of the Pangani Falls, where the river is narrow.

This section is not navigable for any considerable distance on account of the falls, which are about 30 miles (48 km) from the mouth.

Approximately 4 miles (6.4 km) from the mouth, dense mangrove swamp covers the flatland between the hills on either side.

The northern side of the entrance is a flat sandy beach that extends from the head of the bay.

Historically, the town of Pangani, on the river's left bank, had a reputation for fevers.

[14] Average monthly flow of Pangani measured at the hydrological station in Korogwe Estate, about 110 km above the mouth in m³ / s (1959–77).

[18] The PBWB consists of ten professionals from public institutions and private sector LGAs, UWSAs, and other committees.

It receives technical assistance from the International Union for Conservation of Nature (IUCN), the SNV Netherlands Development Organisation, the GIZ German Development Organisation and the local non-governmental organization PAMOJA.

[19] The project also receives funds from the government of Tanzania, IUCN, the European Commission, and the Global Environment Facility through the United Nations Development Programme.

Produce is brought down the river, principally on rafts made of the Moale palm, which are then broken up and become articles of commerce.