Abstract: 99Mo (F.P.) of high purity for medical use is separated rapidly from a mixture of fission products of 235U by means of A12O3 and anion exchange resin columns. The effects of flow rate of moving phase on the recovery of "Mo (F.P.) are investigated in detail. Under the conditions selected, the time for the separation of 99Mo(F.P.) is about 3-4 hours with a recovery of 50-55%. The radionuclidic purity of daughter nuclide 99mTc conforms to standards of European Pharmacopoeia 1981.