The technical demands for magnesium alloys with sufficient mechanical properties at room and elevated temperatures, as well as corrosion resistance are dependant on the desired application. A new class of magnesium alloys based on the Mg-Sn system has been studied with an emphasis on the Mg-Sn-Ca system due to their attractive property profile especially concerning creep resistance. Thiis research work investigates the effect of 3 wt.% Al additions on two selected Mg-Sn-Ca alloys namely the Mg-3Sn-2Ca (TX32) alloy, and the Mg-9Sn-lCa (TX91) alloy at different temper conditions, with the aim of improving room temperature mechanical properties, and corrosion resistance. A comparison of experimental results for the new Mg-Sn-Al-Ca (TAX) alloys, with their base Mg-Sn-Ca (TX) alloys, is performed, and explicitly discussed. The results showed enhanced hardening response in some of the alloys while the corrosion resistance deteriorated significantly. Al additions were found to have a favorable effect on strength of Mg-Sn-Ca (TX) alloys while they caused rapid decrease in their corrosion resistance.