The market share of wrought Magnesium products such as structural and functional components is recently increasing. Extrusion at elevated temperatures is used to produce reliable plastic deformation, since magnesium alloys have limited ductility at room temperature. In order to produce sound extruded products, high quality billets are required. Understanding the influence of direct chill casting conditions on the production properties such as quality, safety, workability and microstructure have a profound importance. Comprehensive computer simulations were used in order to model the casting so that process parameters can be identified and controlled, resulting in significant benefits. The aim of modeling is to provide temperature profiles for a more accurate solidification analysis, predict the solidification time and the effect of cooling on the solidification. The experimental study included castings of several Magnesium alloys, each with 7 (seven) thermocouples that were submerged into the billet. Verification of the simulations was carried out based on the data collected. Complimentary work was conducted on microstructure analysis in as cast and as-extruded states.