A stress analysis was carried out in order to determine the local stress distribution around spherical particles in particulate filled composites. The results were introduced into the criteria for micromechanical deformations and the conditions for the initiation of each mechanism were calculated. Results of the calculations have shown that shear yielding, and possibly crazing, do not depend on thermal stresses and adhesion, but debonding does. The results of the analysis were in accordance with literature and experimental data. The calculated debonding stresses correspond to the observed values, but both debonding and yield stress depend strongly on composition, a phenomenon the analysis does not account for. The discrepancy can be explained with matrix/filler interaction and the role of the interphase. The results indicate that although stress analysis helps to predict deformation and failure in particulate filled composites, it must be further refined to find more exact solutions and the effect of interfacial interactions must also be considered.