Hydrosilation of poly(methylhydrosiloxane) with a fluorinated olefin in supercritical CO2 (scCO(2)) using Karstedt's Pt catalyst has been successfully demonstrated; results were compared with those obtained in a subcritical conventional solvent, i.e. toluene. Rates of hydrosilation were found to be dependent on solvent, reactant concentration, and reaction temperature. Levels of hydrosilation were 40-50%, depending on reaction conditions. Gel formation, which was not observed under any conditions in subcritical toluene, occurred in all reactions done in scCO(2) and accounted for up to 20 wt.-% of the final product mix.