Important efforts are being made to increase electric energy savings in the field of lighting. Of all the different approaches possible, two are used more frequently than others: The use of lighting control systems and the replacement of old light sources with better ones. One direct effect of the employment of new light sources and light dimming controls is a decrease of the power quality of the electrical network. This paper addresses luminous and power quality measurements of different light sources that are suitable for office buildings. The measurements were performed with and without dimming. In this way, the luminous and the power quality characteristics of the light sources, at different light levels, were established.