In Croatia, Sivak families are almost entirely Croats (from Djakovo ), barely Hungarians. In the past century, relatively most of Croatian residents bearing this family name were born in Djakovo and Osijek. In Brijest in Osijek nearly every inhabitant had the family name Sivak.
Prevalence
About 50 people with faimily name Sivak live in Croatia today, in 13 households. There were 30 of them in the middle of the past century, and their number increased by 90 percent. They are located and four other Croatian places, mostly in Budrovci (20), Osijek (15), Tenja (<10), Pula (<5), and in Djakovo (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over ten times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.