This review attempts to answer the following questions: what are the interest and benefits of polymerizing in supercritical media and what type of polymer and polymerization process can be used? Supercritical fluids (SCFs) in theory offer many advantages since they have intermediate properties between liquids and gases. Also, at a time when the environment is undergoing such great impacts as the depletion of the ozone layer by chlorofluorocarbons (CFCs), the use of CO2 seems an attractive alternative for sustainability and conservation. This is why heterogeneous polymerization methods, particularly suspension and dispersion processes, offer great potential with an SCF as a suspending medium. Unfortunately, polyolefins and other commodities, such as poly(vinyl chloride) (PVC), may not benefit from SCF technology today for profitability reasons, but acrylics, styrenics and other fluorinated plastics are open to this new technology, Furthermore, SCFs may have an impact on polyamides, polycarbonates and other speciality polymers.