According to Ecobank Tanzania direct applicable exchange rates for foreign currency transactions to the public, on the week ending February 12th, 2015 USD buying rate was TZS 2,125, while selling rate was TZS 2,250.
A week earlier buying and selling rates where TZS 2,123 and 2,248 respectively, representing an appreciation of 2 Tanzanian Shilling per US Dollar.
See below Ecobank full list of applicable exchange rates for US Dollar, Sterling Pound, Euro, Kenyan Shilling, South African Rand, Japanese Yen and Chinese Yuan Renminbi (CNY).