A single particle diffusion model for estimation of effectiveness factor for a substrate inhibited encapsulated immbolized enzyme particle of spherical shape, which considers both internal and external diffusional resistances has been extended to study the performance of a continuous flow stirred tank reactor (CFSTR) system. The effect of membrane thickness, Sherwood Number, dimensionless inhibitor constant, characteristic CFSTR‐encapsulated enzyme particle parameter, and the ratio of the substrate diffusion coefficients on the substrate conversion are investigated parametrically. The numerical results are obtained for a range of variables of practical importance.