Born as Giovanni Host-Ivessich in Fiume, then Austria-Hungary, Nino Host obtained a license to middle school, and specialized as a dentistry technician.

Between June and July 1920, Host-Venturi also opened a series of secret meetings with Croat (specifically the Croatian Committee), Montenegrin and Albanian separatists to explore the possibility of a concerted campaign that aimed to "prevent the consolidation of the so-called Yugoslavia".

As Secretary of the Merchant Marine Host-Venturi was among those who contributed most to the consolidation of the Finmare, the Italian state shipping financial holding company which covered the maritime sector within Istituto per la Ricostruzione Industriale (IRI).

As war approached Italian territory Giovanni Host Venturi created a special anti guerrilla unit the "Nucleo paracadutisti dalmati" to support the dalmatian Chetniks against Tito's partisans.

Host-Venturi remained at the Ministry of Communications until 6 February 1943, when he was replaced by Senator Vittorio Cini, this time following a massive government reshuffle which saw the removal of fascist authority following the heavy military defeats and the approaching invasion of national territory by the Allies.