Radiopharmaceutical therapy (RPT) is a precision medicine approach that involves the targeted delivery of radioactive atoms to tumor cells, representing a breakthrough strategy for cancer treatment. Radiopharmaceuticals typically consist of a small amount of radioactive material, a radionuclide, paired with a chemical that specifically targets the cell. Some radionuclides naturally target specific cells or biological processes without the need for modification. RPT is a novel cancer treatment method that offers various advantages over current traditional treatment approaches. One of the primary advantages of RPT is its ability to target cancer cells, including those in metastatic areas. Another key advantage of RPT is that radiation can be delivered systemically, locally, or physiologically to specific cells internally rather than being applied externally. Moreover, radiotracer imaging can be utilized to determine radiopharmaceutical absorption in target tissues before providing a therapeutic dose. Compared to all other cancer treatment approaches, RPT has demonstrated high efficacy with minimal toxicity. The recent approval of multiple RPT medicines by the US Food and Drug Administration highlights the tremendous potential of this treatment. This article provides a detailed review of RPT, including insights into manufacturing procedures, safety measures, and its applications in cancer therapy.