In Croatia, Trhaj families are Croats (from Krizevci area ).
Prevalence
About 20 people with faimily name Trhaj live in Croatia today, in two households only. There were 10 of them in the middle of the past century, and their number doubled. They are located in only two naselja i to in Kapela Ravenska in Krizevci area (<5) and Mali Raven (<5).
Outside Croatia
Family name Trhaj (including: Terhaj , Terhai ) is present in three countries on two continents. "Terhai " is used by few people in the United States.