The aim of this work is to explain the optimal voltage regulation in the distribution network through the theoretical and practical part. The introduction lists the four main units of the power system and its main task as well as the two basic types of distribution networks. The second chapter lists the basic equations for the voltage drop along the circuit and the ways in which the voltage drop along the circuit can be reduced. The third chapter describes the voltage drop allocation, the principle of the load flow model and the problems and voltage reduction including the solution of these problems. The fourth chapter describes the principle of operation of the regulator as well as three types of compensation: line-drop compensation, load-center and voltage-spread compensation. Chapters five and six describe the methods for parallel operation of regulators, bus regulation settings and line loss and voltage drop relationships. In the practical part of the work, the optimal voltage regulation is shown using the DIgSILENT PowerFactory program, and the voltage profiles before and after the optimization are compared.