In Croatia, Zajac families are mainly Croats (from Ilok ), equally Slovaks (also from Ilok ). In the past century, relatively most of Croatian residents bearing this family name were born in Ilok and Vukovar.
About 50 people with faimily name Zajac live in Croatia today, in 17 households. There were 60 of them in the middle of the past century, and their number decreased by 20 percent. They are only located in in 6 Croatian cities and four other places, mostly in Ilok (35), Sarengrad (<10), Bilje in Osijek area (<5), Velika Gorica (<5), and in Vukovar (<5).