The Institute of Archaeology (Zagreb) carried out the geophysical research of the late medieval archaeological complex Osijek Vojakovački – Mihalj (Koprivnica-Križevci County) in the cooperation with GEARH Ltd. (Maribor). The site consists of a wooden-earthen fortification (object 1) and the remains of two buildings with stone foundations for which we presume sacral purpose (objects 2 and 3). The basic goal of geophysical research was to evaluate the archaeological potential by creating anomalies maps in different geophysical fields using the georadar method (GSSI SIR3000, 400 MHz antenna), magnetic methods (Geometrics G-858), resistivity mapping method (Geoscan RM15), 2D resistivity tomography (ARES) and low-frequency electromagnetic method (CMD Miniexplorer). The geophysical research has confirmed the potential of the archaeological site and all the necessary data were collected for the purpose of determining the positions of archaeological trenches in future archaeological investigations. Furthermore, new, unknown structures were recognized at this site also which are not recognizable in terrain configuration. This especially refers to clearly recognized elongated building with five rooms in a row which is situated underneath the so called object 3 which appears above the earth as a circular stone building. Such disposition of the architectural remains underneath the surface opens the possibility of existence of a monastery, whereby this particular segment could belong to the northern wing of the monastery building. The rest of the building’s wings are less recognizable on some geophysical recordings in the southern area towards the church (object 2), and are probably less well preserved in their foundations.