Orošnjak families are mainly Croats and they are mostly from Kastel Sucurac , but often Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Split and in Solin area.
Prevalence
About 120 people with faimily name Orošnjak live in Croatia today, in 50 households. There were 80 of them in the middle of the past century, and their number increased by 50 percent. They are located in threee Croatian counties, in 6 cities and four other places, mostly in Kastel Sucurac (85), Split (20), Solin (<10), Sibenik (<10), and in Trogir (<5).
Outside Croatia
Family name Orošnjak 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 2007 in source Encyclopaedia of Croatian Surnames.