In the past century, relatively most of Croatian residents bearing this family name were born in Daruvar area.
Prevalence
About 10 people with faimily name Ružićka live in Croatia today, in 0 households. There were 10 of them in the middle of the past century, and their number remains constant. They are located in one Croatian city only, in Daruvar (<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.