[en] sup(99m)Tc-gluconate complex for renal imaging prepared by labeling of calcium gluconate solution appeared to show some radioactivity accumulated in the liver. For this reason, the use of gluconate complex prepared by tin(2) chloride reduction of sup(99m)TcO₄^- in sodium gluconate solution was investigated. The radiochemical analysis of the separated sup(99m)Tc-Sn-gluconate-(Na) complex was carried out by Whatman 1 paper chromatography using acetone and saline as the mobile phase. The biological distribution test in Swiss mice showed that the sup(99m)Tc-Sn-gluconate(Na) complex was well accumulated in the renal without significant accumulation in the lung or in the liver. Observation on human, both renal pathologically and clinically normal patient, proved that the complex has potential prospect for renal imaging. (author)