Aims: is to evaluate the castability of titanium alloy and compare it with that of nickel-chromium and cobalt-chromium alloys by measuring castability and porosity values. Materials and methods: A total of 30 samples were prepared for castability and porosity tests. Castability was measured by castability test according to Hinman method by measuring the numerical number of the reproduced segments of casting samples . Porosity value was measured by determined the porosity percentage according to (Archimedes) method . ANOVA and Duncun , s multiple range test were carried out to determine the significant difference at p ≤ 0.05% . Results: the results showed that titanium alloy has a lowest value of castability and the highest value of porosity percentage, While cobalt-chromium alloys has intermediate values. Nickel-chromium alloy has highest value of castability and the lowest value of porosity. Conclusion: there is a significant differences between the castabilty and porosity values among different casting alloys used. The differences between the catability values are related to variance between the melting temperature of the different casting alloys, the higher the melting temperature the less castability value.