Daylighting Simulation is a complex task, involving many parameters, but an important step to design buildings, especially when the main purpose is more comfort and energy conservation. For architects, simulation is still something far from the professional practice, due to the software’s complexities, difficulties to use software’s interface, hard interpretation of the results and many other reasons. This article analyses and compares 4 daylighting software: Desktop Radiance, Rayfront, Relux 2004 Vision and Lightscape. The objective of the study is to find the main advantages and limits of each one, taking into account the priorities for the use of the software by the architects in their professional practice. Some criteria like interface, flexibility, help manuals, and others are analyzed, intending to establish a frame of the main points to be considered when choosing daylighting software for architects use, both in architecture schools and offices. The methodology includes simulations with a test room, varying some parameters to verify the performance of the main criteria. The results show the potential of software’s improvement, especially regard ing the user interface and help manuals.