Complex posttraumatic stress disorder (CPTSD) is a diagnostic entity that will be included in the forthcoming edition of the International Classification of Diseases, 11th Revision (ICD-11). It denotes a severe form of PTSD, comprising not only the symptom clusters of PTSD (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV-TR]), but also clusters reflecting difficulties in regulating emotions, disturbances in relational capacities, and adversely affected belief systems about oneself, others, or the world. Evidence is mounting suggesting that first-line trauma-focused treatments, including eye movement desensitization and reprocessing (EMDR) therapy, are effective not only for the treatment of PTSD, but also for the treatment of patients with a history of early childhood interpersonal trauma who are suffering from symptoms characteristic of CPTSD. However, controversy exists as to when EMDR therapy should be offered to people with CPTSD. This article reviews the evidence in support of EMDR therapy as a first-line treatment for CPTSD and addresses the fact that there appears to be little empirical evidence supporting the view that there should be a stabilization phase prior to trauma processing in working with CPTSD.