In Croatia, Mikulaj families are Croats (from Cakovec ). In the past century, relatively most of Croatian residents bearing this family name were born in Cakovec and in Cazma area. In Žabnica in Cazma area every twentieth inhabitant had the family name Mikulaj.
Prevalence
About 50 people with faimily name Mikulaj live in Croatia today, in 20 households. There were 20 of them in the middle of the past century, and their number more than doubled. They are only located in in 6 Croatian cities and 12 other places, mostly in Slemenice (<10), Cakovec (<10), Zagreb (<10), and in Mala Subotica (<5) and Palovec (<5) in Cakovec area.
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.