The CO2 flooding is a proven enhanced oil recovery technique to obtain high oil recovery from complicated formations. It can be injected as immiscible or miscible flooding but immiscible flooding is less effective than miscible flooding. The miscible flooding process involves complex phase behaviour. The CO2 increases oil recovery by oil swelling, reduction of oil viscosity and density, the acidization of carbonate formations and miscibility effects. Multiple-contact miscibility between the injected CO2 and oil can be achieved at pressures above the minimum miscibility pressure (MMP). MMP is the pressure at which the reservoir fluid develops miscibility with CO2 and is a very important parameter in a welldesigned CO2 flooding project. This presentation will briefly address the results of CO2 miscible flooding applied to a known tight reservoir. Several CO2 miscible flooding experiments were conducted using live oil at reservoir temperature and pressure above the MMP on composite cores of the known reservoir. The MMP was determined experimentally using a slim tube device. High oil recovery from these experiments indicates that the MMP determined from slim tube studies was correct and such a high recovery is only possible if full miscibility occurs during the displacement. The analytical correlation also gave a MMP consistent with MMP determined from slim tube experiments.