The official currency of Paraguay is the Paraguayan Peso. However, on October 5, 1943, a law was created replacing the peso at a rate of 1 guarani is to 100 pesos. The history of the Paraguayan Peso can be traced back to 1842 when Carlos Antonio Lopez deemed it necessary to have their own currency since they finally gained independence from Spain. Back before he assumed power, they were all using currencies from other countries, marked only with a little stamp so it could be distinguished as the official currency of Paraguay.
After assuming his office, Carlos Antonio Lopez issued a provision for the creation of paper money on March 1, 1847. However, the Paraguayan Peso was changed to guarani under the government of Higinio Morinigo, the President of Paraguay from 1940 to 1948.