Tc-99m-Methionine complexes from enantiomeric and racemic methionines were prepared controlling reaction parameters such as pH and the concentration of stannous chloride. Some radiochromatographic systems were also examined to determine the labelling yields of Tc-99m complexes. The best resolutions of Tc-99m complexes were obtained at ITLC-SA developed with acetone and paper chromatography with n-butanol saturated with 0.3N HCI. In the former system, HR-Tc-99m and Tc-99m-methionine complex remained at origin, while 99mTcO4 moved with Rf value of 1.0. In latter process, HR-Tc-99m stayed at the origin, while 99mTcO4 and Tc-99m- methionine complexes moved with Rf value of 0.5. By combining of two chromatographic systems, the contents of three Tc-99m species were calculated easily. Tc-99m Labelling from enantiomeric and racemic methionines had little differences and the optimal condition was found at pH 9.00 and the molar ratio of methionine to stannous chloride od 24:1. The yields of Tc-99m complexes from D-, L-, and DL-methionines were 87.6%, 94.1%, and 97.9%, respectively. The results indicated that methionine containing relatively hydrophobic methylthio group (-SCH3) would be labelled with Tc-99m by stannous chloride method.