In Croatia, Kasaić families are Croats (from Petrinja area ). In the past century, relatively most of Croatian residents bearing this family name were born in Sisak and in Petrinja area. In Letovanić in Petrinja area every twentieth inhabitant had the family name Kasaić.
Prevalence
About 50 people with faimily name Kasaić live in Croatia today, in 30 households. There were 80 of them in the middle of the past century, and their number decreased by 30 percent. They are located in threee Croatian counties, four cities and 5 other places, mostly in Letovanic in Petrinja area (15), Zagreb (15), Sisak (15), Staro Pracno (10), and in Rijeka (<5).
Outside Croatia
Family name Kasaić is present in this form only in Croatia.
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.