From its source near Mount Uludağ (the classical Mysian Olympus) and flowing past the city of Bursa, the river tends to the northwest along its course of 203 kilometres (126 mi).

The river may have been named for the flowers or for Nilüfer Hatun, a wife of the Ottoman sultan Orhan.

Writing in the 19th century, John Cramer considered the Nilufer to be the classical Odrysses though noted there were some problems with this.

C. Foss, in compiling Map 52 for the Barrington Atlas, silently rejects this identification, preferring the modern Kara Dere (Karacay; a left tributary of the Simav_River).

[5] It formerly flowed into the Rhyndacus but now joins the Simav (ancient Macestos) north of Karacabey.