Purpose of review Outcomes for children with cancer have improved dramatically. Although the contribution of disease biology and therapy resistance to treatment failure continues to be a focus of intense research efforts, the role of medication nonadherence on the part of caregivers or patients has been relatively neglected. Efforts to further improve childhood cancer cure rates must include a focus on improving medication adherence. Recent findings Recent studies in children with acute lymphoblastic leukemia have conclusively demonstrated that nonadherence to oral antimetabolite therapy is associated with a significant increase in relapse risk. The impact of nonadherence to other oral medications in acute lymphoblastic leukemia and in other childhood cancers remains unknown. Tools by which clinicians can accurately identify nonadherent families are currently being developed but remain suboptimal. Similarly, while current efforts to develop interventions aimed at increasing adherence rates are underway, their feasibility and effectiveness is still unknown. Summary Future studies must focus on the development and widespread implementation of methods by which to identify and minimize nonadherence. Doing so will allow for further improve childhood cancer cure outcomes.