Trstenjak families are Croats and they are mostly from Mursko Sredisce area. In the past century, relatively most of Croatian residents bearing this family name were born in Cakovec and Zagreb.
About 730 people with faimily name Trstenjak live in Croatia today, in 310 households. There were 590 of them in the middle of the past century, and their number increased by 20 percent. They are located in almost all Croatian counties, in 30 cities and 84 other places, mostly in Zagreb (100), Cakovec (65), Belica in Cakovec area (40), Mursko Sredisce (30), and in Varazdin (25).