This dissertation is a modified systematic review with the purpose of exploring the following questions: What is grief? What is complicated grief? How do we work therapeutically with complicated grief? Theoretical perspectives on what constitutes normal grief have evolved from one of placing a time frame for the conclusion of grieving, to accepting that grieving is a unique and varied experience that may take a lifetime to resolve. The significance of this can be demonstrated during periods of loss in adulthood when old bereavements and losses from childhood can be revived. How an individual deals with grief in response to loss is also dependent on a wide range of variables, including the type of relationship to, or nature of, the attachment to what is lost, the circumstances surrounding the loss and whether there has been support from others after the loss. In this the power of community in transitioning through grief is an important part of the grieving process. Ironically, part of the increased use of therapists to work through grief is a result of changes in society and family and social supports being less available. Factors complicating the grieving process include the presence of prior traumatic loss in childhood, individuals with psychiatric illness, and the lack of social support at the time of loss. Often separation distress is at the core of complicated grief. The importance of a good relationship between therapist and client is a strong indicator of a successful outcome where the therapist needs to be mindful of unrealistic assumptions about the process of grieving.