Situated on the gateway to North-West Vietnam, Yen Bai Province borders Lao Cai, Ha Giang in the north, Son La Province in the west, Tuyen Quang in the east, and Phu Tho in the south.
Terrain includes mountain, hill and valley. The network of rivers is complex with many falls and waterfalls. Climate in lowland is different from highland. Annual average temperature is from 18ºC to 28ºC.