He was a non-politician[1] appointed as the first Italian European Commissioner on the Hallstein Commission from January 1958 with responsibility for the Social Affairs portfolio.

In September 1960 (or December 1960, or 8 February 1961) he resigned and was succeeded by Lionello Levi Sandri.

A professor, Giuseppe Petrilli became president of IRI (the Italian Institute for Industrial Reconstruction – a powerful state-owned holding company) in 1960 and served for almost twenty years, until 1979.

Commissioner Petrilli was a member of the 1979 group that produced the Spierenburg Report on the improvement of the working methods of the commission.

[3] A Giuseppe Petrilli, left-wing Italian Christian Democrat (DC) member was appointed secretary general of the "EUCD" in 1978, according to the European Peoples Party.