Magnesium alloys with enhanced thermal stability are being developed for automobile engine applications. The available commercial Mg-alloys are usually alloyed with aluminum that are thermally stable only for T < 150o C. Development of new Mg-alloys is underway and Mg-Sn alloys are a promising option. In Mg-Sn alloy, the Mg2Sn phase has high thermal stability and is expected to enhance the high temperature properties. In this study, Mg-5Sn alloy is incorporated with Ag as a minor alloying element (0.175 wt. %). The creep behavior of the Mg-Sn-Ag alloy is investigated using the impression creep technique. The impression creep tests were carried out under punching stress in the range of 80-320 MPa and temperature of 373-573 K, for dwell times up to 5 hours. The results highlight that creep of the alloy was load and temperature dependent, i.e. increasing the load and temperature resulted in higher creep rates.