Kosor families are Croats and they are mostly from Drnis. In the past century, relatively most of Croatian residents bearing this family name were born in Drnis and Split. In Ostrogašica in Drnis area every fifth inhabitant had the family name Kosor.
Prevalence
About 330 people with faimily name Kosor live in Croatia today, in 130 households. There were 200 of them in the middle of the past century, and their number increased by 60 percent. They are located in 9 Croatian counties, in 16 cities and 16 other places, mostly in Split (80), Trbounje (50), Zagreb (45), Sibenik (30), and in Omis (15).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.