Barnjak families are Croats and they are mostly from middle Bosnia. In the past century, relatively most of Croatian residents bearing this family name were born in Middle Bosnia (Bugojno area) and in Middle Bosnia (Travnik area). In places Crniče , Rastovci and Krupa in Middle Bosnia every ninth inhabitant had the family name Barnjak.
Prevalence
About 230 people with faimily name Barnjak live in Croatia today, in 90 households. There were 0 of them in the middle of the past century, and their number multiplied. They are located in the most of Croatian counties, in 27 cities and 17 other places, mostly in Zagreb (80), Makarska (20), Sesvete (15), Rijeka (10), and in Otok in Vinkovci area (10).
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.