Abstract Heterogeneous materials with special properties dedicated for specific applications attract a lot of interest due to the possibility of designing tailor-made products with strictly desirable properties. Wide range of new heterogeneous systems requires fast and non-destructive techniques for their characterization. The confocal 3D Raman micro-spectroscopy seems to be a powerful method for investigations of such materials. Its major advantage is a wide range of information simultaneously gained from the Raman spectra about the chemical structure, morphology, intermolecular interactions, internal stresses, etc. In this paper we focus our attention on the combination of two confocal Raman microscopy techniques: depth-profiling and mapping. Presented results show that such 3D Raman micro-spectroscopy allows to estimate shapes and sizes of distributed particles even for materials giving very weak Raman signal.