There has been a relative dearth of empirical attention focused on the study of the co-occurrence of posttraumatic stress and panic psychopathology. Since these conditions represent two prevalent and impairing psychiatric conditions, the study of their diagnostic and phenomenological comorbidity is clinically meaningful and theoretically warranted. The articles in this series discuss the possible cognitive-affective mechanisms relevant to both conditions and elucidate innovations in applicable clinical intervention approaches. Thus, the overarching purpose of this series is to underscore key empirical questions, to showcase emerging research, and to stimulate further scientific inquiry into the co-occurrence of posttraumatic stress and panic psychopathology.