Colored dark red on transit maps, the line currently runs from Nhổn, a suburb in Bắc Từ Liêm District, west of city center, to its current terminus in Cầu Giấy Bus Interchange, located in Cầu Giấy district.

[10] Two separate preliminary feasibility studies was conducted in 2004 and 2005 with the help of the Asian Development Bank to determine the viability of Line 3.

Two underground stations, Cát Linh and Văn Miếu, were relocated one block eastward to avoid cultural significant sites.

[13] Beside 276 million euros from the Hanoi city's budget, the project also receives 726 million euros from the four donors - the French government (DGT), French Development Agency (AFD), Asian Development Bank (ADB),[14] and European Investment Bank (EIB).

[15] [16] [17] [18] [19] Line 3: Nhổn - Hanoi Station section starts from Nhổn - to National Highway 32 - Cầu Diễn - Mai Dịch - Ring road 3 intersection - Cầu Giấy (ring road 2 intersection) - Kim Mã - Giang Vo - Cát Linh - Quốc Tử Giám and ends at Tran Hung Dao Street, in front of Hanoi Station.

[20] The 2nd phase of Line 3 will have 7 more stations (Hàng Bài, Trần Thánh Tông, Kim Ngưu, Mai Động, Tân Mai, Tam Trinh, Yên Sở) all being completely underground with 1 depot located near Yên Sở Pumping Station.