[1] Simonsen was appointed Brazil's finance minister by President Ernesto Geisel with instructions to reduce the country's runaway inflation rate.

Despite Simonsen's efforts, the official inflation rate had risen to 40% per annum in 1979 and he was shifted to Planning Minister.

He was succeeded by Antonio Delfim Netto, with whom he had an uneasy relationship due to the latter's inclination to increase borrowing, and hence inflation.

Simonsen resigned from Cabinet in 1980 and became a director of Citicorp, a position he held until 1995 when he was forced by ill-health to retire.

He was married to Iluska Pereira da Cunha Simonsen.