Co-deposition of the Tl-based superconductors using electrodeposition technique was successfully carried out. Different processing parameters such as deposition potential, current density, deposition period etc were studied. The Tl-based alloyed thin films were deposited at a constant potential of-1.25 V with respect to SCE electrode onto silver substrates and oxidized at 850°C in oxygen atmosphere. The samples thus prepared showed superconducting behaviour below 122.5K and the critical current density was 1.5 x 103 AJcm 2. Electrochemical synthesis of Tl-based high Tc single-phase superconductor thin films is also reported.