Nuclear data are important for production and medical application of a radionuclide. This brief review concentrates on nuclear reaction cross-section data. The availability of standardized nuclear data for accelerator-based production of medical radionuclides is outlined. Some new directions in radionuclide applications, for example, theranostic approach, bimodal imaging, and radionuclide targeted therapy, are considered and the status of relevant nuclear data is discussed. The current trends in nuclear data research using accelerators are elaborated. The increasing significance of intermediate energy accelerators in production of therapeutic radionuclides is emphasized.