Multidrug resistance is a major obstacle to cancer treatment and leads to poor prognosis for the patient. Multidrug resistance-associated protein 1 (MRP1) can confer drug resistance in vitro and MRP1 may play a role in the development of drug resistance in several cancers including acute myeloid leukaemia, small cell lung cancer, T-cell leukaemia and neuroblastoma. The majority of patients with neuroblastoma present with widely disseminated disease at diagnosis and despite intensive treatment, the prognosis for such patients is dismal. There is increasing evidence for the involvement of the MYCN oncogene, and its down-stream target, MRP1, in the development of multidrug resistance in neuroblastoma. Given the importance of MRP1 overexpression in neuroblastoma, MRP1 inhibition may be a clinically relevant approach to improving patient outcome in this disease.