Lengwe's topography is unusual for Malawi and consists of open deciduous forests and dense thickets.

Animals that inhabit this park include giraffe, spotted hyena, leopard, warthog, kudu, impala, Samango monkey, reedbuck, Cape buffalo and suni; and many interesting birds, particularly shrikes, rollers, bee-eaters and the Yellow-spotted nicator.

In 1928, Lengwe was established as a Game Reserve to protect the large mammals found in the Lower Shire Valley, especially the nyala antelope and its habitat.

This protection is important as the Lower Shire Valley is the farthest north where nyala can be found naturally.

Lengwe was expanded mainly to protect the catchment areas of the Shire, Mwanza, and Nkombedzi wa Fodya rivers.