In Croatia, Costa families are Croats (from Daruvar ).
Prevalence
About 20 people with faimily name Costa 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 four Croatian cities only: in Zagreb (<5), Rijeka (<5), Zadar (<5), and in Daruvar (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1925 in source Emigration Commission Zagreb.