The potentiodynamic polarization measurement of Sn-8.5Zn-XAl-0.5Ga alloy was carried out in 3.5% NaCl solution. The Al content in the alloy varied from 0.02-0.5 wt %. Addition of Al from 0.02 to 0.05 wt % decreased the corrosion current density and corrosion rate of the alloy. However, for Al content Ͼ0.05 wt % a significant increase in the corrosion rate and corrosion current density was observed. These changes were also noticed in the linear polarization resistance of the alloy. Auger depth profile and secondary ion mass spectrometry results revealed that the outer surface of the passive film was primarily composed of a high concentration of gallium oxide with a low concentration of zinc oxide. Aluminum oxide and tin oxide contributed a little to the formation of the passive film on the outer surface; however, it was present in the sputtered layers. An increase in the Al content to 0.5 wt % shifted the breakdown potential toward more negative values and facilitated the increased adsorption of Cl − ion in the passive layer. The presence of Cl − ion was responsible for the breakdown of the passive film.Lead-containing solder alloys, particularly tin-lead alloys, have been widely used in electronic industries for a long time due to low cost, good soldering properties, adequate melting temperature range, and proper physical, mechanical, metallurgical, and fatigueresistance properties. However, serious concerns on the toxicity of lead have led to an increase in the control and legislation on the use of lead. The use of lead in solders for electronics assembly has not been banned yet, but a strong trend of moving toward a green world is driving the industry to develop lead-free solder alloys with an immense enthusiasm. However, the new lead-free solder alloys which will be used in the electronic industry need to meet a variety of properties, such as good wettability, low melting point, low cost, adequate strength, good thermal fatigue resistance, etc. A number of investigations have been carried out on lead-free alloys such as Sn-Zn, 1-7 Sn-Ag and certain ternary systems such as Sn-Zn-In, 8,9 Sn-Ag-Cu, 10 Bi-Sb-Sn, 11 etc. Addition of Zn 12 to the Pb-free solder alloy results in good mechanical property and fatigue life. The presence of zinc in the solder alloy results in wettability decrease and poorer corrosion behavior of the alloy. The corrosion resistance of Zn has thus been improved by the addition of Al, 13,14 as in the case of conventional galvanized coatings for steel.Lin et al. 15 have studied the corrosion behavior of Sn-Zn-Al and Sn-Zn-Al-In 16 alloys by using potentiodynamic polarization techniques in 3.5% NaCl solution. In one study they found that SnZn-Al alloy underwent more active corrosion than 63Sn-37Pb alloy. In another study 16 they noticed that 5In-9͑5Al-Zn͒-Sn alloy was slightly more susceptible to corrosion than 10In-9͑5Al-Zn͒-Sn alloy. The polarization behavior of these two alloys were similar to that of 9͑5Al-Zn͒-Sn alloy. Recently Mohanty et al. 17 have investigated the effect of Al on the ...