For the hydrogeological characterization of fissured rocks it is very important to know the fissure directions. To determine the dominating directions geophysically, the so-called azimuthal geoelectric measurement had seemed to be a realistic way, until its shortages (false fissure directions in many cases) were revealed. In this paper, we improve the azimuthal measurement, on basis of analogue modelling, by using the Wenner array, which is generally applied in azimuthal measurements. We study how many azimuthal measurements are needed to be carried out to determine the dominating fissure directions (each in different measuring point over the investigated area, instead of one single measurement over the whole area as had been earlier suggested). In the model parameter range, we used to characterise three-directional fissure system, it is possible to apply the anisotropy paradox theory (which is not always the case). As we concluded from the model measurements, in order to determine solely the fissure directions, our improved method seems to be a bit expensive, however it is less expensive than the aquifer test. Involving further arrays, or combining the azimuthal measurements with profile geoelectric measurements, we expect a more reliable solution at a somewhat reduced cost.