He was capobastone (head of command) of the Piromalli 'ndrina based in his hometown Gioia Tauro on the Tyrrhenian coast of Calabria.

[3] In 1967, the court imposed a five-year mandatory internal banishment (soggiorno obbligato) to remove Piromalli from his home town and criminal associates.

[4] Together with Antonio Macrì from Siderno on the Ionic coast and Domenico Mico Tripodo, the boss of the city of Reggio Calabria and the surrounding areas, the Piromalli brothers formed a sort of triumvirate since the beginning of the 1960s until the outbreak of the First 'Ndrangheta war in the mid-1970s.

Through the membership of covert Masonic lodges the 'Ndrangheta bosses were able to contact law enforcement authorities, judges and politicians that were necessary to access public work contracts.

[9][10][11] According to Gaetano Costa (the former chief of the Messina Mafia family turned state witness), "it was Mommo Piromalli who – given the enormous interests which the existed in the Reggio Calabria area (the railroad stump, the steelwork center, and the port in Gioia Tauro, etc.)

Only at the end of the so-called First 'Ndrangheta war, which took place in 1974-76 and led to the deaths of Macrì and Tripodo as well as the rise of Piromalli and the De Stefano brothers as the new leaders of the Reggio Calabria 'ndrine, was the new institution fully recognized.

Getty's grandson was found alive on December 15, 1973, in a Lauria filling station, in the province of Potenza, shortly after the ransom was paid.

[24] Together with his brother Peppe Piromalli, Mommo redirected the 'Ndrangheta clan from its rural base to an entrepreneurial criminal organisation assuming dominance over several public works in the Gioia Tauro area, particularly in the construction and operation of the new container seaport.

[25] When in 1974 businesses involved in the expansion of the port and steelworks in Gioia Tauro offered a three per cent kickback to be left in peace the three leading 'Ndrangheta families at the time, Antonio Macrì, the Piromalli clan and the De Stefano clan rejected the offer and wanted to be sub-contracted on work carried in order to control the project.