Krnjaić families are mainly Serbs and they are mostly from Hrvatska Kostajnica area , whereas often Croats (from Sisak ). In the past century, relatively most of Croatian residents bearing this family name were born in Sisak and in Hrvatska Kostajnica area.
Prevalence
About 270 people with faimily name Krnjaić live in Croatia today, in 150 households. There were 450 of them in the middle of the past century, and their number decreased by 40 percent. They are located in the most of Croatian counties, in 31 cities and 39 other places, mostly in Zagreb (45), Sisak (35), Petrinja (10), Karlovac (10), and in Glina (10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1929 in source Emigration Commission Zagreb.