The main aim of this work is to study the effective elastic modulus of hybrid composites through micromechanical modeling. The micromechanical framework based on the generalized method of cells has been employed for this study. The predictions based on the present model are compared with an assortment of experimental and other theoretical predictions. The effect of two types; sequential mode and mixed mode of filler additions oil the effective elastic modulus of the hybrid composite are studied. Moreover, the effect of other microstructural parameters such as the concentration, shape and aspect ratio of fillers in altering the hybridization effects are also investigated. (c) 2005 Elsevier Ltd. All rights reserved.