Knowledge of carcass quality parameters and composition is crucial to determining the value of the carcass and informing decisions regarding its processing. The use of non-destructive technologies for this purpose is essential to avoid the pdestruction of carcasses and cuts and to reduce waste. This can be achieved through linear measurements, either obtained manually or using semi−/fully automatic devices at the slaughter line. These devices need to be calibrated, and cutting and dissection are used as references for this purpose. This chapter aims to describe the most common carcass quality parameters for characterising carcass composition. Additionally, a list of different aspects that should be considered for device checking and carcass preparation before measuring is provided, as well as the types of measurements possible with each device.