Kopecki families are predominantly Croats and they are mostly from Pleternica area , less frequently Slovaks (from Djakovo area ). In the past century, relatively most of Croatian residents bearing this family name were born in Djakovo area and in Pleternica area.
Prevalence
About 120 people with faimily name Kopecki live in Croatia today, in 50 households. There were 100 of them in the middle of the past century, and their number increased by 20 percent. They are located in the most of Croatian counties, in 11 cities and 24 other places, mostly in Lipovljani in Novska area (25), Djakovo (15), Cacinci in Orahovica area (10), Cepin in Osijek area (<10), and in Zagreb (<10).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over ten times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.