Mrkus families are Croats and they are mostly from Pregrada. In the past century, relatively most of Croatian residents bearing this family name were born in Pregrada and Zagreb.
Prevalence
About 90 people with faimily name Mrkus live in Croatia today, in 40 households. There were 110 of them in the middle of the past century, and their number decreased by 20 percent. They are located in 6 Croatian counties, in 6 cities and 12 other places, mostly in Zagreb (30), Cigrovec (15), Vrhi Pregradski (<10), Hrastelnica (<10), and in Vojsak (<10).
Outside Croatia
Family name Mrkus (including: Merkus , Merkush ) is present in 19 countries worldwide.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 2007 in source Encyclopaedia of Croatian Surnames.