Photovoltaic (PV) systems are increasingly present in the electrical distribution systems due to the governments incentives and low production costs of a developed PV technology. This paper summarizes the measurements on power quality (PQ) parameters carried out in a radial distribution network in two periods of time, before and after connecting a PV plant to the grid, and also shows the same parameters measured in the point of common coupling (PCC) of the grid and PV plant in order to discuss about how the impedance of the grid and ratio between injected power and power demanded by the load may influence changes on the PQ of the distribution system. Some measured values are compared with the limits set in the international standards. This paper assesses the impact of PV generation on the distribution system and important issues such as reverse power flow and harmonic distortion are analyzed.