The present investigation has been carried out in order to propose a new model for the determination of the surface hardness of thin films, employing data easily obtained from standard micro-indentation tests. The model is based on the consideration that the substrate has a predominant behavior at the highest indentation loads, whereas at low indentation loads the predominant behavior is that of the film. Such a description is achieved by combining a series and parallel additive laws associated to each behavior, respectively. This approach has been applied for the computation of the hardness of a number of films, including Al2O3, Cr, diamond like carbon, Ti, TiC, TiCN, TiN, TiNchi and ZrNchi, deposited onto different substrates. It is shown that the results obtained are in good agreement with the predictions provided by other models reported in the literature. (c) 2005 Elsevier B.V. All rights reserved.