The removal of radioactive cobalt from alkaline waste containing sodium has been studied in batch process using two different inorganic compounds (a) hydrous manganese oxide (HMO), and (b) copper hexa-ferrocyanide (CFC) and compared with a strongly acidic cation exchange resin (Dowex50W98). The percentage removal of cobalt was examined by varying experimental conditions, viz. pH of the solution, contact time and interfering ions. The studies showed that HMO can be used as an efficient adsorbent for the removal of cobalt from sodium containing wastes.