In Croatia, Sinko families are Croats (from Cakovec area ). In the past century, relatively most of Croatian residents bearing this family name were born in Cakovec and Zagreb.
Prevalence
About 40 people with faimily name Sinko live in Croatia today, in 18 households. There were 30 of them in the middle of the past century, and their number increased by 20 percent. They are located in four Croatian counties and four other places, mostly in Zagreb (<10), Sisak (<10), Rijeka (<10), Cakovec (<10), and in Strahoninec in Cakovec area (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over ten times, the first time 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.