Gentamycin sulfate (antibiotic) was labelled with99mTc with high radioactive yield. Technetium species were studied using different types of sephadex on columns. Stannous chloride was used as reducing agent for heptavalent99mTc obtained directly from generator to lower oxidation state prior to labelling. Optimal pH was found to form the most stable complex. A lyophilized kit was prepared and it was stable for more than three months. Mice, rats and rabbits have been used as exprimental animals. Accumulation of more than 20% of the labelled formula in kidneys 30 minutes post injection in rats has been found. Gamma camera images in rabbit were clear enough for kidney delineation thirty minutes after injection.