Abstract The main microstructure parameters, namely the volume fraction of the secondary phase, the aspect ratio of whiskers and the mean grain size of matrix measured on three types of structural materials: Si3N4 + SiC whisker, MoSi2 and C/C composite are determined in the paper. Standard methods of quantitative microstructure analysis were used and their results were compared with those achieved by help of image analysis made on DIPS 4.0. Microstructure parameters estimated by automatical image analysis had usually lower values than those achieved by manual methods. It is caused by an inadequate etching of same grain boundaries and by a small contrast between the measured particles and the matrix. In the case of estimation of the aspect ratio of whiskers on the image analysator DIPS 4.0 the difference can be caused by the fact that if calculating on DIPS the main and small radius of Legendre ellipse is taken into account and at the manual estimation the maximum and minimum size of the measured alements.