A radionuclide production method and system makes it possible to separate a target radionuclide generated by irradiation with a radioactive ray, and to reduce the generation of a radioactive waste along with the separation. The radionuclide production method includes irradiating, with a radioactive ray, a target material in which a starting material nuclide is present, to generate a radionuclide; and eluting the radionuclide into a liquid by bringing the target material into contact with the liquid. The radionuclide production system includes a target material having a starting material nuclide; an irradiation unit for the target material that generates a radionuclide; and an elution unit that elutes the radionuclide into a liquid by bringing the target material into contact with the liquid. For both the radionuclide production method and system, the target material is a porous body or a granular material through which the liquid is passable.