In this thesis, the characteristics and capabilities of application of the computer program NEPLAN in engineering practice and for teaching purposes with special emphasis on the module for short circuit analysis are studied. NEPLAN is an extremely powerful software tool that is used to perform analyzes and calculations of various network conditions. The program allows parameterization of elements to the smallest details, and the execution of calculations is very fast. Detailed modeling of system elements ensures this program great accuracy even with many elements in the system. A version of the NEPLAN V553 program was used in this thesis. Following the introductory part, the main characteristics of short circuits according to the standard HRN EN 60909 are described. An overview of the basic formulas for the calculation of short-circuit impedances of electrical elements, required for calculation of short circuit currents, is given. Moreover, the basic components of short circuit currents are described in this chapter of thesis. A description of symmetrical components for four basic types of short circuit and short circuit over fault impedance is also given. The third chapter describes the general part of the NEPLAN program, the layout of graphical user interface and the way of managing data in the program. Also, the most frequently used program modules in the NEPLAN program are described, with special emphasis on the module for short circuit analysis. The fourth chapter describes the method of parameterizing the elements and performing the simulation required for the calculation of short circuit currents. An example of three-phase and one-phase short circuit analysis on selected buses of a given network in the NEPLAN program is given in the fifth chapter. In order to check the accuracy of the results in the NEPLAN program, the calculation of short circuit currents on the same network in the program PowerCAD was performed.