Krošlin families are Croats and they are mostly from Pregrada area. In the past century, relatively most of Croatian residents bearing this family name were born in Slovenia and in Pregrada area. In Brezno Gora in Pregrada area every tenth inhabitant had the family name Krošlin.
Prevalence
About 70 people with faimily name Krošlin live in Croatia today, in 30 households. There were 80 of them in the middle of the past century, and their number decreased by 10 percent. They are located in 7 Croatian counties, threee cities and 15 other places, mostly in Lastine (15) and Donje Brezno (10) in Pregrada area, Zagreb (10), and in Mali Tabor (<10) and Poredje (<10) in Pregrada area.
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.