Porosity is one of the major defects in aluminum castings and results in a decrease of the mechanical properties of Al-Si alloys. It is induced by two mechanisms: solidification shrinkage and gas segregation. One of the methods for complex evaluation of macro and micro porosity in Al-Si alloys is using the Tatur test technique. This article deals with the evaluation of porosity with the help of Tatur tests for selected Al-Si alloys. These results will be compared with results obtained from the ProCAST simulation software.