Janžek families are Croats and they are mostly from Krapina area. In the past century, relatively most of Croatian residents bearing this family name were born in Krapina and in Krapina area.
Prevalence
About 250 people with faimily name Janžek live in Croatia today, in 100 households. There were 130 of them in the middle of the past century, and their number doubled. They are located in the most of Croatian counties, in 20 cities and 31 other places, mostly in Gornje Jesenje in Krapina area (50), Lipovnik in Ivanec area (20), Miholjacki Porec (15), Josipovac (15), and in Velika Ves (15).
Outside Croatia
Family name Janžek (including: Janzek , Yanzek ) is present in four countries on two continents. "Yanzek " is used by few people in the United States.
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.