In Croatia, Mattiassich families are mainly Croats (from Porec ), less frequently Italians (from Buje ). In the past century, relatively most of Croatian residents bearing this family name were born in Pula.
Prevalence
About 10 people with faimily name Mattiassich live in Croatia today, in three households only. There were 0 of them in the middle of the past century, and their number multiplied. They are located in only threee naselja i to in Buje (<5), Cervar-Porat (<5), and in Cancini (<5).
Outside Croatia
Family name Mattiassich is present in 6 countries on four continents.
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.