The preparation of a single-component kit for (99m)Tc-MIBI requires stringent control of lyophilization conditions. Hence, a two-components kit formulation, lyophilized under normal conditions, was standardized. The ligand was kept separate from the reductant stannous tin (preserved as stannous glucoheptonate) and advantage was taken of transchelation method, of Tc-GHA and Cu(I)-MIBI, for formation of Tc-MIBI. The product obtained was comparable in radiochemical purity (95 ± 2%), in heart uptake (2% injected dose) in rats and in blood clearance in rabbits, to that of the single- component kit/commercial product. Good-quality heart images in dog and monkey were also obtained.