Škornjak families are Croats and they are mostly from Petrinja. In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Petrinja.
Prevalence
About 80 people with faimily name Škornjak live in Croatia today, in 30 households. There were 100 of them in the middle of the past century, and their number decreased by 30 percent. They are only located in in 6 Croatian cities and threee other places, mostly in Zagreb (50), Strasnik (10), Petrinja (<10), Pula (<5), and in Zapresic (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.