Potential step transients were investigated as an in-situ probe of epitaxial growth for electrodeposited conducting metal oxides of the Tl2O3 and PbaTlbOc systems. Changes in the induction time and growth type were observed for Tl2O3 deposition as a function of the substrate. The substrates studied were glassy carbon and -textured Pb0.8Tl0.2O1.9· T12O3 deposited onto the glassy carbon electrode showed a distinct induction time, the magnitude of which was potential dependent. Also the type of growth was characterized as three dimensional with instantaneous nucleation. X-ray diffraction of this film shows a nearly random pattern. The potential step transient for Tl2O3 deposited onto the -textured Pb0.8Tl0.2O1.9, showed the absence of an induction time and elimination of the growth segment. The type of growth was characterized as two dimensional. X-ray diffraction indicated epitaxy was obtained for the Tl2O3 films which grew two dimensionally onto the -textured mixed oxide.