A petrophysical investigation was carried out on the hydrocarbon deposit, which occurs in East Moravia near the village Zdanice at the depth of 1 km. The objective of investigations was to find out whether there is a significant difference in the radioactivity of the rock and in other studied parameters between rocks above the deposit and rocks from a distance of 2–3 km. Shallow boreholes were drilled above the deposit and in its vicinity to get rock samples (claystones and siltstones — CLS and sandstones — SNS). Petrophysical parameters — densities, porosity, magnetic susceptibility, radioactivity, and contents of carbon and sulphur were determined and statistically evaluated. Statistical tests of difference between petrophysical parameters of rocks over the oil deposit and outside the oil deposit show a low indicative power of separate petrophysical parameters, while their comprehensive application may enhance their petroleum indicative value.