Octenjak families are Croats and they are mostly from Vrbovca. In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Vrbovec. In Poljana in Vrbovec every seventh inhabitant had the family name Octenjak.
Prevalence
About 100 people with faimily name Octenjak live in Croatia today, in 40 households. There were 150 of them in the middle of the past century, and their number decreased by 40 percent. They are located in threee Croatian counties, in 6 cities and 8 other places, mostly in Poljana (35), Zagreb (20), Vrbovec (15), Senkovec in Zapresic area (<10), and in Naselje Stjepana Radica (<10).
Outside Croatia
Family name Octenjak 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 1902 in source Hartmann's General List of Apartments in Zagreb.