Preparation of BaTiO3 thin films on titanium substrates by hydrothermal-electrochemical methods at temperatures ranging from 80 to 200°C have recently been reported in literature. In the present work, polycrystalline, homogeneous, and electrically insulating films of BaTiO3 have been electrochemically synthesized at temperatures as low as 55°C. Effects of various electrochemical and thermodynamic parameters such as temperature, solution pH, electrolyte composition, current density, and atmosphere on phase stability and film characteristics have been investigated. Formation of BaTiO3 is favored only under highly alkaline conditions. This finding is consistent with the reported phase stability criteria for BaTiO3 in Ba-Ti-CO2-H2O system. Auger spectroscopic analyses with depth profiling indicate a titanium oxide layer, whose thickness depends on current density, acts as a precursor to BaTiO3. Use of highly oxidizing atmospheres promotes the formation of thick, well-crystallized and electrically insulating films of BaTiO3 at low temperatures. Films synthesized at 55'C exhibit a characteristic bilayer structure consisting of a large grained porous top layer above a fine grained and dense bottom layer. In contrast, the films prepared at higher temperatures are uniform, fine grained but porous. Preliminary experiments indicate the feasibility to electrochemically synthesize BaTiO3 at temperatures near 25°C.