Mrdalj families are predominantly Serbs and they are mostly from Knin area , less frequently Croats (from Zadar). In the past century, relatively most of Croatian residents bearing this family name were born in Benkovac and Zadar. In Prović in Benkovac every tenth inhabitant had the family name Mrdalj.
Prevalence
About 120 people with faimily name Mrdalj live in Croatia today, in 70 households. There were 250 of them in the middle of the past century, and their number halved. They are located in the most of Croatian counties, in 16 cities and 12 other places, mostly in Ervenik in Knin area (20), Zagreb (15), Pozega (15), Split (15), and in Rijeka (<10).
Outside Croatia
Family name Mrdalj is present in 11 countries worldwide. The family name "Mrdalj " is used by small number of people in the United States and small number in Austria.
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.