Mrnjavac families are Croats and they are mostly from middle Bosnia. In the past century, relatively most of Croatian residents bearing this family name were born in Middle Bosnia (Kiseljak area) and in Middle Bosnia (Sarajevo area). In places Toplica , Žeželovo and Kuliješ in Middle Bosnia every fourth inhabitant had the family name Mrnjavac.
Prevalence
About 90 people with faimily name Mrnjavac live in Croatia today, in 30 households. There were 10 of them in the middle of the past century, and their number multiplied. They are located in the most of Croatian counties, in 11 cities and 12 other places, mostly in Bocaki in Zlatar area (20), Sesvete (10), Rijeka (10), Zagreb (10), and in Zadar (<10).
Outside Croatia
Family name Mrnjavac is present in 11 countries worldwide. The family name "Mrnjavac " is used by some 50 people in Sweden , small number in Austria , and small number of people in the United States.
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.