Ružak families are Croats and they are mostly from Krapina area. In the past century, relatively most of Croatian residents bearing this family name were born in Krapina and in Krapina area.
Prevalence
About 150 people with faimily name Ružak live in Croatia today, in 70 households. There were 250 of them in the middle of the past century, and their number decreased by 40 percent. They are located in 9 Croatian counties, in 14 cities and 16 other places, mostly in Zagreb (35), Lepajci (25), in Cret (20) and Krapinske Toplice (15) in Krapina area, and in Benkovo (<10).
Outside Croatia
At least three families with this surname emigrated from Croatia to the United States. Family name Ružak (including: Ruzak , Ruzhak ) is present in 13 countries worldwide. The family name "Ruzak " is used by some 100 people in Ukraine , about 80 in the United States , and small number of people in Germany.
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.