Šimašek families are Croats and they are mostly from Nasice. In the past century, relatively most of Croatian residents bearing this family name were born in Nasice and in Pleternica area.
Prevalence
About 60 people with faimily name Šimašek live in Croatia today, in 30 households. There were 40 of them in the middle of the past century, and their number increased by 40 percent. They are located in 6 Croatian counties, in 7 cities and 7 other places, mostly in Nasice (15), Velika Gorica (<10), Koska in Nasice area (<10), Pozega (<10), and in Osijek (<10).
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.