In Croatia, Košarač families are Croats (from Samobor area ). In the past century, relatively most of Croatian residents bearing this family name were born in Samobor area and in Zagreb.
Prevalence
About 20 people with faimily name Košarač live in Croatia today, in 8 households. There were 30 of them in the middle of the past century, and their number decreased by 10 percent. They are located in only two naselja i to in Rakitje (15) and Sveta Nedelja (<5) in Samobor area.
Outside Croatia
Family name Košarač is present in two countries on two continents. The family name "Kosarac " 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 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.