The Politecnico has been called as such since 1937, but prior to this it existed as a higher technical institute from 1863. On 29 January 1944, Gino Cassinis was elected as Dean. With Cassinis, the Polytechnic became an important centre of operations for the Resistance. The university became the SAP's weapons depot and the site of a clandestine radio centre. Some lecturers, such as Francesco Moschettini and Michelangelo Böhm, were arrested and deported. Other victims in the fight for freedom included the architecture student Giorgio Labò, who was shot in Rome on 7 March 1944, and Gianfranco Mattei, a lecturer in analytical chemistry, who was arrested and tortured in Via Tasso, where he killed himself on 7 February 1944.

During the April 1945 uprising, the university was militarily occupied by the 116th Garibaldi Division. on 28 April 1945, in a university lecture hall, the former secretary of the Italian Communist Party, Achille Starace, was tried, and later shot in Piazzale Loreto. Cassinis, who had already become a member of the Comitato Onoranze Caduti per la Libertà (Committee for Honouring the Fallen for Freedom), remained Dean until 1960, before being appointed Mayor of Milan from 1961 to 1964, the date of his death.

On 29 September 1945, 'Il Politecnico. Contemporary Culture Weekly' was published for the first time. The Founder and Director was Elio Vittorini, a Sicilian and former translator and writer. He moved to Milan in 1939 to work at Bompiani, with whom he had published Conversazione in Sicilia and Uomini e no. The office was located at 29 Viale Tunisia. The publisher was Einaudi and the graphics were taken care of by Albe Steiner. The title was reminiscent of Carlo Cattaneo's nineteenth-century journal, whose anti-academic, pragmatic and popular tone was intended to be taken up without giving way to the 'popular'. The editorial board included Franco Calamandrei, Franco Fortini, Vito Pandolfi, Albe Steiner and Stefano Terra.

The last issue of the weekly 'Politecnico' was the 28th issue. With issue No.29, dated 1 May 1946, the magazine instead became a monthly magazine. The editorial office initially moved to Via Filodrammatici 5, and then returned to Viale Tunisia with issue no.34. Vittorini remained editor, but there was no longer a real editorial office. Giuseppe Trevisani was the editorial secretary. The magazine reorientated its approach, distancing itself from the previous encyclopaedic zeal to 'create and educate while popularising'. The publication ended in December 1947.