Drug repurposing is a strategy that aims to develop novel cancer treatments through the reuse of existing medicines developed in other disease areas. Such a strategy includes the identification of candidate drugs, clinical development, drug licensing, reimbursement and clinical implementation. This review outlines a literature-based approach to candidate selection with illustrative examples in osteosarcoma, pancreatic cancer and perioperative therapies. Key issues related to the development of clinical trials, drug licensing/approval and clinical adoption are explored to highlight some of the obstacles that must be overcome to successfully repurpose a drug as a new therapeutic option.