Mrak families are Croats and they are mostly from Delnice area. In the past century, relatively most of Croatian residents bearing this family name were born in Rijeka and Zagreb.
About 330 people with faimily name Mrak live in Croatia today, in 140 households. There were 340 of them in the middle of the past century, and their number remains constant. They are located in the most of Croatian counties, in 19 cities and 40 other places, mostly in Rijeka (50), Zagreb (25), Trviz (20), Bjelovar (15), and in Ravna Gora in Delnice area (15).