The inclusion of complex posttraumatic stress disorder (CPTSD) in the 11th revision of the International Classification of Diseases is an important development in the field of psychotraumatology. Complex PTSD was developed as a response to a clinical need to describe difficulties commonly associated with exposure to traumatic stressors that are predominantly of an interpersonal nature. With this special section, we bring attention to this common condition following exposure to traumatic stressors that only recently has been designated an official diagnosis. In this introduction, we review the history of CPTSD as a new condition and we briefly introduce the papers for the special section in the present issue of the Journal of Traumatic Stress. It is our hope that the work presented in the special section will add to an ever‐expanding evidence base. We also hope that this work inspires further research on the cultural validity of CPTSD, its assessment, and treatment.