In a radial distribution system, which is typical for Ethiopian electric power distribution network, not only a substantial amount of power is lost but also the voltage profile of distant nodes from the main supplying substation are frequently below the minimum threshold value(0.95pu) especially during heavy load conditions. This in turn exposes the end consumers to continuously suffer from under-voltage problem. The primary leading factors for the occurrence of these problems are improper network configuration and very high resistance to reactance ration of the distribution lines. In this thesis, Particle Swarm Optimization (PSO) based simultaneous distribution network reconfiguration and optimal Distributed Generation (DG) integration is conducted to significantly minimize the power losses and enhance the voltage profile of the network. Two additional tie-switches are added in the network in order that the network reconfiguration can be optimally altered with the help of many tie-switches and their locations were determined considering geographical constraints, line length between non-consecutive nodes and voltage profile of the sending and receiving nodes. The resource feasibility of solar and wind energy in Bahir Dar town was assessed and the results revealed that solar energy production is more preferable. As a result, solar type DG which injects only active power to the system is used and its optimal size and location is identified using PSO algorithm. Backward/forward load flow analysis is deployed so as to determine the power losses and the voltage profile of each buses in the system. The proposed method is tested using MATLAB software in one of Bahir Dar distribution feeders called Bata feeder, and the objective function is evaluated by considering numerous constraints such as radiality, voltage profile, DG output limit and branch current limit. The simulation results obtained using simultaneous distribution network reconfiguration and DG insertion are encouraging. The voltage magnitude of all nodes is above the minimum threshold value and the minimum voltage is enhanced from 0.9150 pu to 0.9600 pu. In addition to this, the active and reactive power loss reduction are 54.42% and 46.37%, respectively. The cost effectiveness of the required DG size is also scrutinized and the payback period has become nearly four years.