Resumen: Hot rolling of steels involves not only geometrical and final shape requirements but also, in a significant number of cases, microstructural conditioning in order to achieve the final required mechanical properties. In those situations, a proper understanding, evaluation and control of the microstructural changes that occur at each step of a rolling schedule is necessary. The objective of this chapter is to describe the main metallurgical aspects that intervene during hot rolling, focusing on those that are relevant for achieving the proper final mechanical properties. In the first part of the chapter the microstructural changes that take place during hot rolling will be considered, taking into account mechanisms such as recovery, recrystallization, strain induced precipitation and the different interactions between them, concluding with the relationship between austenite microstructure, cooling conditions and final room temperature microstructure. In the second part, the relationship between room temperature mechanical properties and microstructure will be evaluated. Special emphasis will be given to the differences between mean attributes and local heterogeneities. Taking the concepts described in these two sections as a starting point, the next section will be devoted to the main aspects of the thermomechanical processes. The last part of the chapter will focus on considerations regarding the effect of several metallurgical factors on the mechanical properties.