Cyclic voltammetric experiments were carried out on platinum in acidic solution (pH 3) containing ferrous sulfate, nickel sulfate and ethylamines (EtNH2, Et2NH, Et3N). Spectral ultraviolet absorption studies indicate the complexation of both Fe2+ and Ni2+ ions with ethylamines. The results under transient polarisation conditions indicate the reduction of Fe2+ ions through the intermediate species FeOH+, with second electron transfer as a slow step. The higher charge transfer rate of FeOH+ over NiOH+ reduction causes the anomalous codeposition of Fe-Ni alloy film. Among the ethylamines, Et3N considerably assists the alloy deposition process. A gradual variation in free energy of alloy formation with Fe2+:Ni2+ (mol:mol) in the bath suggests the formation of an alloy intermediate phase rich in iron. Stripping voltammetric curves indicate the preferential dissolution of iron from iron rich alloy intermediate phase. X-ray diffraction studies further confirm the phase to be b.c.c. Fe-Ni alloy. The extent of corrosion of the Fe-Ni alloy film in the presence of ethylamines is in the following order: Et3N > Et2NH > EtNH2.