There were several grain mills in the upper part of the town, powered by stream water. The first mill, called Gomila, was situated upstream from the Cross at the crossroads, approximately ten meters away from Milka Babić's house. Following Gomila, there were other mills such as Bjelovac, located near the spring of the same name, as well as Pravdaš, Halatin, Marolic, and Gornji mills.

In addition to the water mills, the people of Zrin had three manual mills (žrvanj) for grinding corn flour. During the summer when the water flow in Zrinčica was low or non-existent, they utilized a steam/fire mill. The approach road to this mill was often filled with horse and carts waiting for their turn. The Brkić brothers, consisting of five brothers, owned and operated the steam/fire mill, with two of them working in the mill.

In the lower part of the town, there was Kasmovac mill next to the spring of the same name. Further down in the field at the end of the village, there was another mill known simply as "the mill below the church." These mills were collectively owned by the villagers, and a schedule was followed to ensure fair usage among the townspeople.