Just as traumatic experiences may lead to posttraumatic stress disorder (PTSD) in some individuals, grief may also be a serious health concern for individuals who have experienced bereavement. At present, neither the DSM-IV nor the ICD-10 recognizes any form of grief as a mental disorder. The aim of this review is to summarize recent advances in definition, assessment, prevention, and treatment of complicated grief disorder (CGD) and to compare CGD with PTSD. Four areas are identified to be of importance to clinicians and researchers: (a) the recently proposed consensus criteria of CGD for DSM-V and ICD-11, (b) available assessment instruments, (c) recent prevention and treatment techniques and related effectiveness studies, and (d) emerging disorder models and research on risks and protective factors. This review focuses on the similarities and differences between CGD and PTSD and highlights how a PTSD-related understanding aids the investigation and clinical management of CGD.