In Croatia, Jamšek families are Croats (from Ozalj ). In the past century, relatively most of Croatian residents bearing this family name were born in Rijeka.
Prevalence
Only a few people with faimily name Jamšek live in Croatia today, in three households only. There were 30 of them in the middle of the past century, and their number decreased significantly. They are located in two Croatian cities only, in Zagreb (<5) and Vuketic (<5).
Outside Croatia
Family name Jamšek (including: Jamsek , Yamsek ) is present in 12 countries on four continents. The family name "Jamsek " is used by some 60 people in Australia , about 50 in the United States , and small number of people in Germany. "Yamsek " is used by small number of 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 1942 in source Phone Directory of the Independent State of Croatia 1942.