Investigators of sibling bereavement contend that the death of a sibling represents a unique and intense loss experience. The empirical literature, however, lacks conceptual clarity about the characteristics of sibling bereavement. Metaphors of siblingship are widely applied and may compromise the integrity of theory development specific to sibling bereavement, particularly as this knowledge base is broadened. There is an immediate need to extend the descriptive knowledge base for sibling bereavement beyond adolescence, in large part to prepare to address the needs of the great number of adults whose brothers and sisters have died as a result of AIDS. The purpose of this article is to examine the concept of sibling bereavement by reviewing the empirical literature and by applying the Wilsonian Method (1963) of concept analysis. A preliminary model addressing the factors of critical attributes and personal outcome variables for bereavement research specific to sibling loss is presented.