Broiler chicken performance is highly affected by environmental conditions inside the barn. The main parameters that must be considered in terms of thermic confort are temperature, relative humidity and air velocity. This article reviews the effects of these parameters and their interactions on broiler production and describes the state-of-knowledge of Computational Fluid Dynamics (CFD) used in the design of broiler houses, in order to establish priority research areas in this scope. The design and operation of boriler farms must ensure optimal conditions to avoid heat stress and allow the animals to express their genetic potential. It is well known that the design and management of broiler barns has a clear impact on the environmental conditions occuring inside the building. The use of CFD has been widely used to understand and improve these design and operation parameters in livestock buildings. Computational Fluid Dynamics analyzes mass and heat flows inside the building, and the distribution of temperature, relative humidity and air velocity at animal level can be predicted. Therefore, this tool allows testing different solutions prior to their construction reducing thus the number of experimental procedures needed.