Oštarjaš families are Croats and they are mostly from Ivanec area. In the past century, relatively most of Croatian residents bearing this family name were born in Ivanec area and in Varazdin.
Prevalence
About 70 people with faimily name Oštarjaš live in Croatia today, in 30 households. There were 70 of them in the middle of the past century, and their number remains constant. They are located in threee Croatian counties and 6 other places, mostly in Klenovnik in Ivanec area (50), Zagreb (10), Staznjevec (<10), Lepoglava (<5), and in Sveti Ivan Zelina (<5).
Outside Croatia
Family name Oštarjaš is present in three countries on two continents.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 2007 in source Encyclopaedia of Croatian Surnames.