In Croatia, Siretz families are Croats (from Zagreb ). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb.
Prevalence
Only a few people with faimily name Siretz live in Croatia today, in two households only. There were 0 of them in the middle of the past century, and their number multiplied. They are located in one Croatian city only, in Zagreb (<10).
Outside Croatia
Family name Siretz is present in four countries on two continents. "Syretz " 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 1902 in source Hartmann's General List of Apartments in Zagreb.