Among other issues, the former mayor of Buenos Aires will have to tackle slow growth driven by unsustainable spending and inflation at well above 20 percent.
Mauricio Macri meanwhile acknowledged the need to reach out to rivals, calling for unity after his narrow election win, as Argentine voters laid bare the country's divisions.
Conservative opposition candidate Mauricio Macri won Argentina's presidential election on Sunday after promising business-friendly reforms to spur investment in the struggling economy.
He becomes only the third non-Peronist leader since the end of military rule in 1983.
"Scioli did not manage to differentiate himself from Fernandez and so people stopped seeing him as a change of style and went over to Macri", said political analyst Mariel Fornoni.
"This feels like a dream", said 43-year-old doctor Angela Torres at Macri's headquarters, which pulsed with Latin music and was festooned with white and sky-blue balloons, the colors of the Argentine flag.
Opposition Leader Macri Wins Argentina's Presidential Election
"Capital controls are a mistake". She has bent the central bank to her will, muzzled the government's statistics institute and bullied the media.
Policy changes such as eliminating export taxes and quotas on corn and wheat shipments and revamping economic data long viewed as manipulated by Fernandez's government will be quick hits to underscore his intent to bring change. Three exit polls also pointed toward a Macri victory.
"Macri understands what the country needs to do to regain the confidence of global investors and get the economy back on its feet", said Andrew Stanners, investment manager at Aberdeen Asset Management.
"I am not going to appoint an Economy Minister, there will be a Treasury and Finance Minister, plus five other members, who will complete the team, so they can immediately make contact and determine what the real (economic) situation is". The plan is to reduce the kind of power wielded by current Economy Minister Axel Kicillof or Domingo Cavallo during the 1990s, he said last week. That would be a huge change for a continent where many countries, including neighbors Chile, Brazil and Bolivia, have left-leaning democratic governments that have maintained close ties with Venezuela.
Among South American nations, Venezuela stood out in its reaction to Macri's victory.
Macri's supporters swarmed to the Obelisk in the heart of Buenos Aires' theater district for a giant street party as subdued ruling party candidate Daniel Scioli conceded defeat.