In Croatia, Petoljak families are Croats (from Sveti Ivan Zelina area ). In the past century, relatively most of Croatian residents bearing this family name were born in Sveti Ivan Zelina area.
Prevalence
Only a few people with faimily name Petoljak live in Croatia today, in one household only. There were 0 of them in the middle of the past century, and their number remains constant. They are located in only one small Croatian place, in Beloslavec in Sveti Ivan Zelina area (<5).
Outside Croatia
Family name Petoljak is present in this form only in Croatia.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1923 in source Emigration Commission Zagreb.