The identification of patients that will or will not respond to a specific chemotherapy or targeted therapy has the potential to assist in the treatment and management of childhood and adult cancer patients. In vitro laboratory-based assays for determining the sensitivity of patient-derived cells to specific anticancer agents provides a means of optimising the chemotherapeutic regimen for a specific patient and potentially improve treatment response rates. As part of the larger Zero Childhood Cancer Personalised Medicine Program and a national clinical trial initiated in 2017, the ACRF Drug Discovery Centre for Childhood Cancer has implemented an in vitro drug sensitivity testing platform, using highly sensitive cell viability assays and high content imaging, to assess the sensitivity or resistance of childhood cancer patient cells to a range of chemotherapeutic and targeted drugs. In this presentation, we review the in vitro drug sensitivity testing platform, highlight examples of cell testing and discuss the potential of this platform for rapidly finding the right treatment for the right patient, especially for high risk patients that will not respond to current standard-of-care and those patients that undergo relapse and require new treatment plans.