In recent years, mRNA therapeutics have emerged as a promising platform in treating a wide range of diseases, including cancers, infections, genetic disorders, and autoimmune diseases. This review focuses on the clinical impact of mRNA-based treatments and their transformative potential in modern medicine. mRNA therapeutics utilize the host's cellular machinery to produce target proteins, enabling highly specific and customizable treatments. In the case of cancer, mRNA vaccines to stimulate immune responses against such tumor-specific antigens are being developed in a personalized manner. Infectious diseases are also an indication for which mRNA vaccines have shown a significant effect on preventing viral infection, as the global success of mRNA COVID vaccines demonstrates. Among genetic disorders, mRNA therapy presents a new way to restore defective proteins and reverse the underlying pattern of genetic defects. Furthermore, mRNA treatment of autoimmune diseases aims to generate immune tolerance and avoid traditional immunosuppressive therapy. Advances are being driven by the discovery of new technologies to stabilize, deliver, and modulate the immune system around mRNAs. Recent advances in delivery systems and RNA stabilization have further expanded the potential of mRNA vaccines for viral diseases. mRNA therapeutics have the advantage of being rapidly developed and adaptable to a wide range. Research on further improvement of the delivery mechanisms and long-term safety will be necessary for extending the clinical applications of mRNA therapeutics.