The district was established in 1972 by merging the former districts of Dingolfing and Landau (Isar). Its original name wasUntere Isar ("Lower Isar"), but in 1973 it was renamed and got its present name.
The region is characterised by very plain countryside and several rivers running from southwest to northeast (towards theDanube). Most important rivers of the district are theIsar and theVils.