This paper describes the mechanical and physical characteristics of the various members of the flysch rock mass. Laboratory and field tests were performed in the area of northern Istria in order to better understand the characteristics of soft rocks on the basis of the obtained results, as well as to indicate the reliability of a particular testing method for very complex material such as flysch. During field testing, an assessment of the rock mass weathering degree, at the foot of Uĉka mountain was performed and higher degrees of weathering were obtained. In the field, uniaxial compressive strength tests were carried out using a geological and Schmidt hammer, while a Point Load Test was performed in the laboratory (PLT method). Limestone, siltstone and sandstone were tested, and the obtained results differ depending on the used method. The strength values obtained with Schmidt hammer outweigh the smaller values than the strength obtained by the Point Load Test. It is known that the PLT experiment is more reliable and, if carried out properly, prescribed by the standard can give valid results. When tested with Schmidt hammer, an error simply occurs due to the surface characteristics of the rock material being tested and the orientation of the hammer, or the overall method application.