Guyed masts are a key component of the telecommunications infrastructure in several countries. Due to their characteristics, these structures are particularly susceptible to dynamic loading originated from strong winds, causing several collapses in recent decades.These structural failures evidence the need to improve the computational models currently used in the design process. The design process is generally based on simplified computational models of the structure, assuming simplified characteristics of its geometry or constructive design values which generally differ from the real characteristics. In the present work, a comparison is made between the modal characteristics and the structural response obtained for two computational models of an existing tower. In the first case, an idealized model of the structure is used, while in the second case, an updated model based on a field study is used. The results obtained show that the modal displacements are the modal parameter most sensitive to structural variations, whereas the study of the structural response of the tower reveals that the updated model presents efforts up to 50% larger on the structural elements for the analyzed wind loads, due to its initial configuration influenced by the asymmetrical prestressing of the cables.