[en] The therapeutic radiopharmaceuticals labelled by β-particle emission radionuclide are now increasingly used in nuclear medicine. Rhodium-105 (¹⁰⁵Rh) is one of the radioisotopes that can be used for therapy due to its β-particle emission having t_1/2 = 35.4 h, E_β = 247 keV (30%) and 560 keV (70%). In addition to these β-particle emissions, ¹⁰⁵Rh also emits γ-rays of 306 keV (5%) and 319 keV (19%). Those energies range are also suitable for imaging during therapeutic applications. The preparation of carrier free ¹⁰⁵Rh conducted by using natural ruthenium (Ru) target that was irradiated at TRIGA 2000 Bandung reactor has been studied. The irradiated target was oxidized by potassium metaperiodate (KlO₄) and potassium hydroxide (KOH) then dissolved in double distilled water under gentle warming. After that, the solution was extracted with carbon tetrachloride (CCl₄) solution to separate ¹⁰⁵Rh from radionuclidic impurities viz ⁹⁷Ru and ¹⁰³Ru. The solution was further extracted with tributyl phosphate to separate ¹⁰⁵Rh from ¹⁹²Ir as radionuclidic impurity. The last step, the solution was passed through the cationic exchange column (Dowex 50 resin) to separate ¹⁰⁵Rh from cationic K⁺. The optimum condition of ¹⁰⁵Rh preparation was obtained by 4 repetition extraction using CCl₄ followed by 3 repetition extraction using tributyl phosphate. The radiochemical purity of ¹⁰⁵RhCl₃ was determined by paper chromatography, thin layer chromatography and paper electrophoresis techniques. The activity of ¹⁰⁵RhCl₃ as well as its radionuclidic purity were determined by using multi channel γ-ray spectrometer (MCA). The specification of obtained ¹⁰⁵RhCl₃ solution were as follows: p H of 1.5 - 2, clear, activity of 35 - 60 mCi, radioactive concentration of 7 - 12 mCi/ m L, radiochemical purity of 98.90 ± 0.6 %, and radionuclidic purity more than 99% (99.78 ± 0.03 %). In order to obtained suitable p H and high stability of ¹⁰⁵RhCl₃ solution, this radionuclide is under investigation. Owing to the results, ¹⁰⁵RhCl₃ can be used as an alternative radionuclide for therapeutic applications with high specific activity radiopharmaceuticals i.e ¹⁰⁵Rh-EDTMP. (author)