Pietro died from a debilitating illness. His passing left Leorio feeling deeply remorseful about being unable to save his friend, as the illness was entirely curable, but required a surgery he could not afford. Since then, Leorio aspires to become a doctor and takes part in the 287th Hunter Exam.
- Pietro is his name in the 1999 anime adaptation. In the manga and 2011 anime, his name was never mentioned.
- Both Leorio and Pietro were adults during the latter's death, implying that Leorio's dream of becoming a doctor is a fairly recent one. In the 2011 anime, Pietro passed away while they were still children or in their early teens.