Tachov District borders Germany in the west. The terrain is hilly and along the state border, the landscape is mountainous. The territory extends into four geomorphological mesoregions: Plasy Uplands (most of the territory), Upper Palatine Forest (west), Upper Palatine Forest Foothills (a strip along the Upper Palatine Forest) and Teplá Highlands (northeast). The highest point of the district is the mountain Havran in Lesná with an elevation of 894 m (2,933 ft). The lowest point is the Hracholusky Reservoir in Erpužice at 353 m (1,158 ft).
From the total district area of 1,378.4 km2 (532.2 sq mi), agricultural land occupies 652.0 km2 (251.7 sq mi), forests occupy 601.4 km2 (232.2 sq mi), and water area occupies 26.8 km2 (10.3 sq mi). Forests cover 43.6% of the district's area.[1]
The only important river is the Mže, which flows across the district from west to east and forms a deep valley. Its longest tributary is the Úhlavka. The central part of the territory is rich in ponds. There are also two reservoirs, Lučina and partly Hracholusky.