Monofluorocyclopropane isomerizes at 475 °C to formcis- andtrans-1-fluoropropene, 2-fluoropropene, and 3-fluoropropene. The relative amounts of these products formed are pressure dependent. It is shown that, using the previously determined Arrhenius parameters for the formation of each product, RRKM theory does account satisfactorily for the pressure dependence of the product yields forallthe reaction products.