Potočnjak families are Croats and they are mostly from Varazdin area. According to some sources they are from Senj and Karlobag. In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Cakovec. In Greda in Vrbovec every seventh inhabitant had the family name Potočnjak.
Prevalence
About 270 people with faimily name Potočnjak live in Croatia today, in 120 households. There were 290 of them in the middle of the past century, and their number decreased by 10 percent. They are located in the most of Croatian counties, in 22 cities and 33 other places, mostly in Zagreb (45), Rijeka (35), Zadar (15), Petrijanec in Varazdin area (15), and in Razanac in Nin area (15).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over fifty times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.