Purpose: The concept of liminality has been applied to both the experience of adolescence and to the experience of a cancer diagnosis. The aim of this study was to explore how the concept of liminality can be applied to a cohort of patients experiencing both adolescence and cancer concurrently. Methods: Thematic analysis was applied to data from interviews with 17 participants who had been treated for cancer between the ages of 15 and 24 in an adult hospital. As the analysis developed, it became apparent that liminality was a useful conceptual framework to be applied to the data. Results: Participants experienced the liminality of both adolescence and cancer. Four subthemes revealed the interaction of these two liminal states: an oscillation between childhood and adulthood; a disassociation from noncancer peers; a strong connection with other adolescents and young adults (AYAs) with cancer; and a lack of connection with older cancer peers. Conclusion: A model of dual liminality provides a unique conceptualization of the AYA cancer experience. Cancer in the AYA years is depicted as a navigation of two compounding transitional periods. Adolescence and cancer exacerbate one another and impede the AYA's ability to progress through either. It is this compounding of two transitional periods that makes the model of dual liminality valuable to an understanding of AYAs with cancer.