Power quality is a matter of great concern for residential and commercial installation as well as for industry and electrical utilities. Taking into consideration the amount of lighting devices present in the above types of electrical systems, the investigation of their impact on power quality has become quite important. In this way, this paper studies the interaction between electronic and electromagnetic ballast fluorescent lamps and power quality. A combination of measurements and computer simulations using commercial types of devices is used. To illustrate the effect, an office building comprising nonlinear and linear loads, as well as different types of lighting is considered. The final harmonic distortion, active/reactive power loading, power factor, neutral current, etc are then analyzed for the two types of fluorescent ballast.