This paper considers the case of childhood mourning in which there is an increased possibility of a pathological grief reaction, due to an incapacity to sustain mourning and an inability to comprehend death. The death of a sibling in childhood is a complex loss to manage, the outcome of which is inextricably linked with parental grief. Maladaptive parental mourning processes, including the phenomenon of the ‘replacement child’, are explored. The effects of this loss on the surviving sibling can give rise to a variety of symptoms that may impair emotional development. Amongst the main responses experienced by the surviving sibling is that of a guilt reaction, not only for having survived when the sibling did not, but also a fear that harboured death wishes may have caused the tragedy. Premature death anxiety and distorted concepts of illness are further possible outcomes of this event. It is suggested that the primary deprivation a child may experience when their sibling dies is the emotional absence of their parents who are preoccupied with their own grief.