In Croatia, Šišinjak families are Croats (from Jastrebarsko area ). In the past century, relatively most of Croatian residents bearing this family name were born in Jastrebarsko area. In Lasinja in Jastrebarsko area every fiftieth inhabitant had the family name Šišinjak.
Prevalence
About 10 people with faimily name Šišinjak live in Croatia today, in 6 households. There were 10 of them in the middle of the past century, and their number remains constant. They are located in two Croatian counties, in one city and another small place , mostly in Zagreb (<5) and Lasinja in Jastrebarsko area (<5).