Currently most magnesium alloys are based on the Mg-Al system and this system is reasonably well developed. Nevertheless, the alloy system has some disadvantages - while having excellent castability and adequate room temperature mechanical properties Mg-Al alloys show poor creep resistance. This has led to investigations in other magnesium based systems; magnesium forms alloys with a large number of elements and, indeed a number of magnesium systems show good creep resistance. In this work, the Mg-Sn system has been chosen for study. The Mg-Sn system shows some positive characteristics in terms of potential creep resistance; a high temperature stable phase is formed with magnesium - Mg2Sn (melting point: 770°C) and this phase forms as a line compound (71 wt% Sn), which is typically distributed around the grain boundaries. The effect of the addition of a range of ternary elements on the microstructure and creep properties has been studied.