Stefano Monastero (born March 4, 1889- died Aug. 6, 1929) was a mob boss that led a clan of the Pittsburgh underworld during the later Prohibition Era, supplying sugar and other bootlegging commodities.
Monastero and his brothers Lorito and Sam Monastero were the sons of New Orleans crime family Mafioso, Pietro Monastero, who was hanged from a lamp post for the murder of Detective David Hennesey along with many other mafiosi in one of the largest lynchings in American history.
Monatero's group eclipsed that of Salvatore Calderone, another Pittsburgh mobster, who retired. The Monastero organization, largely comprised of immigrants from the area of Caccamo, Sicily, briefly lost ground to Luigi "Big Gorilla" Lamendola in the mid-1920s. Lamendola, a castoff of Al Capone's gang in Chicago, increased in strength until he was shot down in front of his Chatham Street restaurant headquarters on May 20, 1927. Monastero's gang is also believed responsible for the bombing of a rival bootleg supply warehouse in 1929.
Monastero and his brother Sam were murdered in front of St. John's General Hospital on Aug. 6, 1929. Joe "the Ghost" Pangallo was suspected of orchestrating the hit.