The essay focuses on the main stages of the history of Porto Marghera in its hundredth anniversary, with particular regard to the making of the industrial working class and the consequences of the industrialization on the city of Venice. Porto Marghera’s earliest development took place in the interwar period, taking advantage from public benefits and the huge availability of workers from the countryside. After World War II, the trade unions established roots in the factories and a new working class, more radical in its political behavior in particular in the petrochemical sector, emerged. Since the end of the 60’s the issues of work harmfulness and environmental protection became central, provoking the dramatic contradiction between the safeguard of Venice and the lagoon and the industrial development. Workers’ struggles failed in leading a sustainable restructuring of the industrial port, that underwent in the 80’s a progressive decline in terms of production and employment, still ongoing.