In this study a method is developed to determine the stress fields in composite materials. Far-field strains which are assumed to be measured or calculated by using the classical methods, are considered as known inputs. By using an elasticity analysis the interface strains of the different materials in the composite are determined. Nonlocal elasticity is taken as a basis, and the long-range effects of the different material regions on each other are expressed as the heterogeneity effects. Since the far-field strains, calculated by using anisotropic elasticity, are used as inputs, the anisotropy is taken into account in addition to inhomogeneity. Therefore separate stress fields in the different materials of the composites are determined without ignoring either heterogeneity or anisotropy. Different versions of the method are developed for a few typical composite structures. The method is presented for a laminated composite, a three-dimensional continuous fiber-reinforced composite, a thick section and a two-dimensional crack problem. In the laminated composite case the results are compared to a classical solution and the exact laminate solution, and it is seen that the nonclassical method agrees with the exact solution very well. In the other cases the sample results obtained by using the nonclassical method developed in this study, are compared to those of the classical solutions. In this study the method is developed and presented for a few basic composite structures;​ several suggestions are made for more complicated and realistic cases future studies.