In Croatia, Petrinšak families are Croats (from Klanjec area ). In the past century, relatively most of Croatian residents bearing this family name were born in Klanjec area and in Osijek area.
About 60 people with faimily name Petrinšak live in Croatia today, in 20 households. There were 40 of them in the middle of the past century, and their number increased by 40 percent. They are located in 6 Croatian counties, four cities and 10 other places, mostly in Osijek (20), Zagreb (10), Jezera on the Island of Murter (<10), Sveti Kriz in Klanjec area (<10), and in Kladnik in Pregrada area (<10).
Family name Petrinšak is present in this form only in Croatia.