Integrative psychotherapy is the most common approach to clinical practice. In this article we present the historical development of this broad and varied tradition, and describe the most commonly discussed forms of integration: technical eclectisism, the common factors approach, theoretical integration, and assmiliative integration. Furthermore, we present a more recent metatheoretical trend where integration is perceived as a processual activity, devoting more attention to our relationship to knowledge and theory than to the specific theories themselves. The integrative tradition is based on a broad range of empirically documented aspects of psychotherapy, and the role of clinical theories has been subject to debate. Using the case of Nadine, we demonstrate the ongoing integration of clinical theory, techniques and common principles of change in the current process. Keywords: integration, eclectisism, common factors, therapist’s role, alliance