In Croatia, Hrastovski families are Croats (from Hrvatska Kostajnica area ). In the past century, relatively most of Croatian residents bearing this family name were born in Hrvatska Kostajnica area and in Sisak.
Prevalence
About 10 people with faimily name Hrastovski live in Croatia today, in 6 households. There were 30 of them in the middle of the past century, and their number decreased significantly. They are located in only four naselja i to in Sisak (<10), and in Gradusa Posavska (<5), Sunja (<5) and Donja Letina (<5) in Hrvatska Kostajnica area.
Outside Croatia
Family name Hrastovski is present in this form only in Croatia.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1917 in source List of Dignitaries, Officials and Public Servants of the Kingdom of Croatia-Slavonia.