The solvent and swelling effects of supercritical CO2 on coal structure and porosity were examined using high-resolution field-emission scanning electron microscopy (FE-SEM) and surface area techniques to investigate any irreversible CO2 induced alterations of the micro-, meso-, and macropores. Dry, 1in. unconfined cores of Pittsburgh and Sewickly bituminous coals were exposed to supercritical CO2 at 15.3MPa (2200psig) and 328K (55°C) for 104days. Prior to CO2 exposure, coal structure and porosity – specifically macropores (>50nm) – were imaged using FE-SEM. After CO2 exposure, the imaged features were relocated, reimaged, and analyzed for structural changes. Brunauer–Emmett–Teller (BET) surface areas were evaluated from the adsorption isotherms of N2 at 77K and P/P0=0.1–0.3. Micropore surface areas were determined from the low-pressure adsorption isotherms of CO2 at 293K using the Dubinin–Polanyi equation. FE-SEM analysis indicated that there were no significant changes observed in the pore areas in all coal samples after CO2 exposure. Meso- and micropore characteristics were slightly affected by supercritical CO2 exposure.