In Croatia, Ustić families are mainly Croats (from Djakovo area ), less frequently Serbs, and very rarely Montenegrins (from Pula ). In the past century, relatively most of Croatian residents bearing this family name were born in Vrlika and Zagreb. In Otišić in Vrlika every eighth inhabitant had the family name Ustić.
Prevalence
About 30 people with faimily name Ustić live in Croatia today, in 15 households. There were 140 of them in the middle of the past century, and their number decreased significantly. They are located in 6 Croatian counties, in 9 cities and threee other places, mostly in Pula (15), Split (<5), Zagreb (<5), Petrinja (<5), and in Ostrovo in Vinkovci area (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 2007 in source Encyclopaedia of Croatian Surnames.