Born at Viggiano, in the province of Potenza, De Lorenzo started playing the flute at the age of 8 and went to Naples to attend the Music conservatory "San Pietro a Majella".

In 1914, during his collaboration with the Minneapolis Symphony Orchestra, he met Maude Peterson, a pianist who frequently accompanied him and became his wife.

In 1917, the Los Angeles Flute Club played a musical in his honor and De Lorenzo was appointed the first Honorary Member of the association.

From 1923 to 1935 he was professor for flute at the Eastman School of Music, where one of his students was Julius Baker, considered one of the greatest American flutist of his generation.

In the same year, he received an honorary doctorate of the Washington International Academy of Rome and was godfather for the newly formed flute club in Milan.