Sonoelastography is a modern ultrasound method, which enables the representation of tissues and organs with the evaluation of their elasticity, "stiffness". The principle of elastography is to use repeated, slight pressure on the examined organ with the ultrasound transducer. Changes in elasticity and deformation of tissues arising whilst the compression is processed and presented in real time with color-coded maps, is called elastograms. The method is applicable mainly in diagnosing malignant lesions. Tumor tissues have different elasticity and undergo different deformations under pressure than healthy tissues. As a result of computer analysis, images in various colors are generated. Based on the nature of areas of normal and increased stiffness classifications of the images in point scales have been developed. Ultrasound devices equipped with sonoelastography option enable more accurate imaging and evaluation of the nature of lesions situated at small depth, e.g. breast, thyroid, testicles, prostate, some groups of lymph nodes. They increase the accuracy of ultrasound in diagnostics and the evaluation of the stage of malignant lesions. This also helps to indicate more precisely the areas that require the biopsy.