Čosić families are usually Croats and they are mostly from middle Bosnia , rarely Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Middle Bosnia (Jajce area) and in Zagreb. In Merdani in Middle Bosnia every fourth inhabitant had the family name Čosić.
Prevalence
About 130 people with faimily name Čosić live in Croatia today, in 70 households. There were 650 of them in the middle of the past century, and their number decreased significantly. They are located in almost all Croatian counties, in 41 cities and 38 other places, mostly in Zagreb (45), Split (15), Belisce (<10), Srijedska in Bjelovar area (<10), and in Osijek (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over fifty times, the first time 1749 in source 18th Century Census.