The inclusion of feedback in Intelligent Tutoring Systems (ITS) is important to provide support to students when the tutor is not present. Moreover, even more important, is that feedback takes into account affective aspects to improve the student–system interaction. Integrating affective aspects of learning systems improve motivation, study interests, and eventually improve learning outcomes. This book introduces systematically the integration of an affective feedback to an ITS. First, this text relates to a general view of topics about ITS, feedback, and affectivity in face-to-face scenarios and affective feedback in learning systems. In the second instance, based on the information provided by the literature, it defines an Affective Feedback Model (AFM) to improve student motivation, and also it describes the implementation of the Affective Feedback System (AFS) in an instant message box and its integration to an ITS.