In Croatia, Petto families are Croats (from Osijek ). In the past century, relatively most of Croatian residents bearing this family name were born in Osijek and Zagreb.
Prevalence
About 10 people with faimily name Petto live in Croatia today, in five households only. There were 10 of them in the middle of the past century, and their number remains constant. They are located in two Croatian cities only, in Osijek (<10) and Zagreb (<5).
Outside Croatia
Family name Petto is present in 20 countries worldwide. The family name "Petto " is used by some 400 people in the United States , about 400 in Germany , and some 200 people in Brazil.