Systemic-relational psychotherapy is an approach aimed at promoting evolutionary relational conditions that facilitate the emergence of possibilities and resources in individuals and their significant systems. It is based on a systemic matrix (mainly Batesonian), a clinic attentive to social contexts and current problems, a critical and ethical view very attentive to the therapist and the therapeutic systems in which he participates. The different chapters of this work traverse to different extents four axes: 1) complexity in terms of theoretical articulations and relational understandings; 2) a second-order gaze that permanently returns to the therapist and to his self-observation within the network of ongoing processes; 3) an epitemological perspective that invites us to think about ourselves, connected with our clients and with broader systems; and, 4) a therapeutic practice understood as a transformative device of relational conditions that passes through the individual, his or her significant system and other systems in relationship, including the therapeutic until reaching a macro context. The purpose of this book is to share with the Spanish-speaking public some of the most current developments, in prominent and prestigious voices, that have impacted the field of psychotherapy, the multiplicity and diversity of approaches that give an idea of ​​the complexity of the movement, the new practices and understandings that each of the authors propose in innovative ways and that can be used and transformed by those who practice psychotherapy, adapting them to their own contexts and work modalities.