Between 2003 and 2004 he was an adviser for the Subsecretariat for Small and Medium Enterprise and Regional Development, where he specialized in the resolution of the economic asymmetries between Argentina and Brazil in the context of Mercosur.

Before taking the post of Minister of Economy, he had been the senior vice president of the Bank of Investment and Foreign Trade (BICE), as well as the Secretary of Industry, Commerce and Small and Medium Enterprises.

He was considered personally close to former President Kirchner, and kept an amicable relationship with both Chief of Cabinet Alberto Fernández and Minister of Federal Planning Julio de Vido, as well as with Martín Redrado, head of the Central Bank of Argentina.

The former minister expressed strong support for several of the key ideas of the government's economic plan, including the encouragement of industrial exports and import substitution through a relatively undervalued exchange rate sustained by frequent U.S. dollar purchases by the Central Bank.

[4] He was appointed president of BICE following the end of his tenure, but ongoing disputes with the powerful Commerce Secretary, Guillermo Moreno, led to Peirano's resignation in July 2009.