A novel mathematical model to simulate the growth of engineered cartilage on polymeric scaffolds performed in rotating bioreactors is proposed. The dynamic-spatial behavior of the nutrient species (oxygen) and the primary extra-cellular matrix product (GAG) are quantitatively described through the proposed model where the simulation of cell proliferation and its distribution within the polymeric scaffold is improved with respect to the existing literature by properly taking into account suitable population balances. Model results and literature experimental data in terms of GAG contents and its distribution within the tissue construct have been successfully compared, thus demonstrating the validity of the proposed model as well as its predictive capability. (C) 2004 Elsevier Ltd. All rights reserved.