Kiseljak 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 area and in Zagreb. In Orehovec Radobojski in Krapina area every fifth inhabitant had the family name Kiseljak.
Prevalence
About 370 people with faimily name Kiseljak live in Croatia today, in 160 households. There were 410 of them in the middle of the past century, and their number decreased by 10 percent. They are located in the most of Croatian counties, in 24 cities and 37 other places, mostly in Zagreb (85), in Orehovec Radobojski (35) and Jazvine (25) in Krapina area, Krapina (20), and in Bregi Radobojski in Krapina area (20).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over thirty times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.