In Croatia, Jednačak families are Croats (from Novska area ). In the past century, relatively most of Croatian residents bearing this family name were born in Sisak and Zagreb. In Lonja in Sisak every seventh inhabitant had the family name Jednačak.
Prevalence
About 50 people with faimily name Jednačak live in Croatia today, in 30 households. There were 70 of them in the middle of the past century, and their number decreased by 30 percent. They are only located in in 10 Croatian cities and threee other places, mostly in Zagreb (25), Sisak (<10), Samobor (<10), Kastel Sucurac (<5), and in Lonja (<5).
Outside Croatia
Family name Jednačak is present in three countries on two continents. The family name "Jednacak " is used by few 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.