Procedures of image analysis for determination of grain size distribution of compact psammitic rocks and geocomposite materials based on sands grouted with polyurethane resins are presented in the paper. It can be concluded from the experimental results that the image analysis represents an effective tool for assessment of grain size and morphology of compact granular geo-materials. This is a relatively cheap and not time-consuming way of granulometric analysis usable in engineering geology, geotechnics and construction or building-restoration practise