Kasum families are Croats and they are mostly from Imotski area. In the past century, relatively most of Croatian residents bearing this family name were born in Imotski area and in Split. In places Opanci and Lovreć in Imotski area every fiftieth inhabitant had the family name Kasum.
Prevalence
About 120 people with faimily name Kasum live in Croatia today, in 70 households. There were 160 of them in the middle of the past century, and their number decreased by 30 percent. They are located in 8 Croatian counties, in 11 cities and 9 other places, mostly in Split (45), Zagreb (30), Opanci in Imotski area (15), Osijek (10), and in Valpovo (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1930 in source Emigration Commission Zagreb.