Pu Luong proposed nature reserve is located in Quan Hoa and Ba Thuoc districts, in north-western Thanh Hoa province. To the north-east, the nature reserve is bordered byMai Chau, Tan Lac and Lac Son districts, Hoa Binh province. The proposed nature reserve lies along two parallel mountain ridges, that run from north-west to south-east, and are bisected by a central valley. This valley contains several human settlements and a large area of agricultural land, and, hence, is not included within the proposed nature reserve.
The two mountain ridges in the proposed nature reserve have starkly contrasting landforms, based on their different substrates. The smaller, south-western ridge is made up of mostly igneous and metamorphic rocks, and consists of rounded forested hills and wide, shallow valleys. The larger, north-eastern ridge is composed of heavily dissected limestone karst, and is a continuation of the limestone range that runs from Cuc Phuong National Park to Son La province. Elevations in the proposed nature reserve range from 60 to 1,667 m.