Sunko families are Croats and they are mostly from Drnis. According to some sources they are from Poland. In the past century, relatively most of Croatian residents bearing this family name were born in Split and Drnis.
Prevalence
About 100 people with faimily name Sunko live in Croatia today, in 50 households. There were 70 of them in the middle of the past century, and their number increased by 40 percent. They are located in 8 Croatian counties, in 14 cities and 9 other places, mostly in Zagreb (30), Split (25), Sibenik (<10), Rijeka (<10), and in Knin (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over twenty times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.