The parallel implementation of Monte Carlo reaction models for kinetically coupled reaction systems is discussed in the context of a BBN TC2000 MIMD architecture. A comparatively simple Rice-Herzfeld co-pyrolysis reaction scheme is utilized to develop four modelling strategies encompassing "full system", "partial system", "fixed-time", and "variable-time" simulation approaches. The parallel efficiency of the partial system approaches was good. The partial system variable-time algorithm was then applied to simulate the pyrolysis of a complex petroleum resid to demonstrate the scale-up characteristics of the parallel algorithms. The resulting parallel efficiency was excellent (> 90%). These results indicate that the Monte Carlo modelling approach is sufficiently robust to handle kinetically coupled systems, and that the approach is highly parallel.