This study explored the experiences of families when a child with cancer relapses. The aim was to develop an understanding of the human actions and emotions that shape the experience of relapse, to question what influences the care provided at relapse, and to challenge current practices. Twelve families were involved in a critical ethnography exploring their child's relapse. Each family participated in an average of 4 in-depth interviews (46 in total) over a period of 6(1/2) to 13 months. The most significant finding from this study was the profound impact of uncertainty. The families fluctuated between 2 states of reality-hoping for a cure and contemplating death-as they faced the uncertainty that surrounded their child's prognosis. A conceptual model of uncertainty at relapse is presented, demonstrating how uncertainty is significant to the child and family's experience, impacting the pursuit for cure, treatment-related decision making, and prognostic communications. Acknowledging the uncertainty of relapse and developing an awareness of the child and family's hopes and fears may lead to a greater understanding of the challenges faced and promote more open and honest communications at this critical period.