In Croatia, Tustanić families are Croats (from Pleternica area ). In the past century, relatively most of Croatian residents bearing this family name were born in Pleternica area and in Nova Gradiska.
Prevalence
About 10 people with faimily name Tustanić live in Croatia today, in five households only. There were 10 of them in the middle of the past century, and their number remains constant. They are located in threee Croatian counties, in one city and two other places, mostly in Oriovac in Pleternica area (<10), Sunja in Hrvatska Kostajnica area (<5), and in Zagreb (<5).
Outside Croatia
Family name Tustanić is present in three countries on two continents. The family name "Tustanic " is used by few people in Canada and few people in the United States.
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.