Positive psychology stood out against the pathogenic model of mental illness. It focused on the positive features that promote individual well-being. After a long period of time, it is possible and desirable, to overcome the contrast between the positive and the negative, so typical in the Western culture. Positive psychology is a scientific approach concerning both positive and negative human experiences; it studies human strengths, virtues, and positive emotions, but it can be also applied to disabilities and psychopathology, with the aims of prevention and psychotherapy. The integration between positive psychology and psychotherapy can allow to positive psychology to benefit from a wide experience in the personal change setting, and can allow to psychotherapy to broaden its horizons and to increase its effectiveness. Among the different types of psychotherapy, the cognitive-behavioural approach shares with positive psychology some fundamental assumptions and various intervention strategies.