The questions regarding the improvement of the learning system and the perfection of the quality are highly important in the work of teachers of mathematics at universities. One of the possibilities to make students interested to study mathematics is presenting the material by using its visualization. Visualization in teaching mathematics can be a powerful tool to explore mathematical problems and to imagine mathematical concepts and the relationship between them, to perform mathematical experiments and simulations. The paper is devoted to the authors' experience in using visualization techniques in teaching mathematics. There are many different software packages that can be used for creating illustrations or/and animations for problems from different study courses. The talk deals with such special tools as GeoGebra, Mathematical Visualization Toolkit (MVT), Microsoft Project, RStudio, Java Modelling Tools (JVT). By discussing some specific examples of problems from Mathematical Analysis, Methods of Optimization, Operations Research, Numerical Methods, Probability Theory and Mathematical Statistics, the authors show how the considered tools could be effectively used for illustration of theoretical results or solving problems during the practical works. The possibility to use the mentioned tools for the analysis of real-world systems working out study projects and bachelor's theses is also discussed.