region located in western Guinea-Bissau. Biombo region surrounds (but does not administratively include) Bissau, the national capital. The regional capital is located at Quinhámel.

The western and northern borders of the region are formed by the Mansôa River, which flows east-west and empties into the Atlantic Ocean. The western half of the region is forested with mangroves. In the east are dispersed grazing land for cattle, sheep, and goats as well as scattered farmland used for subsistence agriculture that produces corn (maize), millet, and sorghum. Rice and oil palms are cultivated throughout the region. A road from Quinhámel stretches southwestward to the Atlantic Ocean and southeastward to Bissau. The Pepel are the main ethnic group; the other groups are the Balante and the Malinke. Pop. (2004 est.) 63,835.