Monte Carlo methods were tested with respect to their potentials and limitations for the modelling of the kinetics of polymerization reactions and especially with regard to the various distributions of the final product. Presented here is a model concept based on a critical comparison of algorithms already published in the literature. The concept can be used generally and guarantees a high level of formalism and, therefore, a minimum developing time. It is based on the simulation of the time behaviour of molecules in small volume increments of the reaction mass and permits the calculation of kinetics as well as different product distributions. In the case of free radical polymerization reactions, computation times may be reduced if the chain length of the polymer molecules are calculated from the lifetimes of the radicals. The model concept has been tested on the modelling of several different polymerization reactions, such as a heterogeneous polycondensation, an inverse emulsion polymerization and a thermal polymer degradation.