In this paper, asphaltenes are precipitated from a medium crude oil using a non-hydrocarbon precipitant (CO2) or a hydrocarbon precipitant (n-pentane). First, the onset pressure of asphaltene precipitation from the medium crude oil-CO2 system is determined using a visual high-pressure saturation cell. Second; the morphology of CO2-precipitated asphaltenes (CO2-asphaltenes) is examined and compared to that of n-pentane-precipitated asphaltenes (C-5-asphaltenes). Third, the precipitated asphaltenes and deasphalted oils (i.e., maltenes) of the medium crude oil CO2 and medium crude oil n-pentane systems are characterized by applying a variety of analytical techniques, such as the density and molecular-weight measurements, nuclear magnetic resonance (NMR) spectrometry, Fourier transform infrared (FTIR) spectrometry, and simulated distillation. It is found that the onset pressure of asphaltene precipitation from the medium crude oil-CO2 system is equal to 3.8 MPa. The yields and physicochemical properties of the precipitated asphaltenes and deasphalted oils strongly depend upon the specific precipitant used. CO2-asphaltenes are small particles dispersed in the co-precipitated resins, whereas C(5-)asphaltenes are solid-like dark brown and brittle powders. In addition, CO2-asphaltenes have a lower molecular weight, low aromaticity, and shorter aliphatic side chains than C-5-asphaltenes. On the other hand, CO2-deasphalted oil (CO2-maltenes) has a higher molecular weight, high aromaticity, and longer aliphatic side chains than n-pentane-deasphalted oil (C-5-maltenes). The compositional analysis results of CO2-maltenes and C-5-maltenes indicate that the carbon numbers of most precipitated asphaltenes are larger than C-50 and that CO2-maltenes are heavier than C-5-maltenes.