Among Mediterranean historical buildings, the Andalusí architecture is the result of an intuitive and experimental process of adaptation to the surrounding environment. The medieval Muslims coped with difficult climatic conditions in al-Andalus through passive cooling strategies, paying attention also to the thermal comfort. The paper focuses, in particular, on natural ventilation in the Infants’ Tower in the Alhambra of Granada. It has eight mashrabiyas at the top whose performance is investigated through a CFD model, in order to understand their contribution to the improvement of indoor thermal comfort and rational energy use during summer.