The cathodic and anodic deposition of thallium as a pure metal or its oxide from different baths containing Tl(I) or Tl(III) nitrates with some suitable additives has been investigated. The quantity and quality of the metal and its oxide have been found to be dependent on the type of the bath used. The effect of different parameters such as pH (1-12), current density (0.01-4.0 A dm(-2)), temperature (20-60 degrees C), electrode type (platinum and graphite), metal and additives concentration on the cathodic and anodic efficiencies and on the quality of deposit has been studied. The interfering effect of some cations and anions has also been studied. Spectrophotometric, polarographic, AAS and X-ray diffraction techniques revealed the purity of Separated deposit to be 99.9%. A suitable mechanism for the formation of the element and its oxide is suggested. An analytical application for preconcentration and separation of thallium from its natural ores and alloys using the proposed electrolytic method has been found to be satisfactory and successful.