In Croatia, Šlafer families are generally Croats (from Novska area ), very rarely Serbs. In the past century, relatively most of Croatian residents bearing this family name were born in Novska area and in Novska.
Prevalence
About 20 people with faimily name Šlafer live in Croatia today, in 8 households. There were 20 of them in the middle of the past century, and their number remains constant. They are located in threee Croatian counties, two cities and 5 other places, mostly in Jazavica (<10), Ustica in Novska area (<10), Goli Breg (<5), Vir in Nin area (<5), and in Zagreb (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1923 in source Emigration Commission Zagreb.