<p>Reactor-based production of medical radioisotopes plays a critical role in modern nuclear medicine. The performance, safety, and reliability of this production route depend strongly on materials used in target preparation, irradiation containers, shielding systems, and radiochemical processing facilities. This review discusses the influence of materials science on key stages of reactor radioisotope production, including target material selection, irradiation capsule design, radiation shielding, and post-irradiation radiochemical processing. Particular emphasis is placed on the physicochemical properties of target materials, isotopic enrichment, corrosion resistance, thermal stability during irradiation, and compatibility with separation processes. The review also examines representative production routes for important radionuclides used in nuclear medicine, including ⁹⁹Mo/^99mTc, ¹³¹I, ¹²⁵I, ¹⁵³Sm, ⁸⁹Sr, ¹⁸⁶Re, ¹⁸⁸Re, ⁹⁰Y, and ³²P. In addition, radiation shielding requirements for both <i>γ</i>- and <i>β</i>-emitting radionuclides are discussed, highlighting the use of high-Z materials such as lead for <i>γ</i>-radiation and low-Z materials such as polymethyl methacrylate and polyethylene for <i>β</i>-radiation shielding. Overall, the review emphasizes the importance of materials engineering in ensuring efficient, safe, and sustainable production of reactor-produced medical radionuclides.</p>